DRAFT GUIDELINESJuly 2007 THESE GUIDELINES RELATE TO THE REGULATIONS GOVERNING THE LABELLING AND ADVERTISING OF FOODSTUFFS, R642 OF 20 JULY 2007 TABLE OF CONTENT TI TLE OF GUIDELINE WHO’s DIETARY AND HEALTH GOALS PROTEIN DIGESTIBILITY-CORRECTED AMINO ACID SCORE (PDCAAS) • • • • Method to determine the PDCAAS of a protein or mixed protein Example: Calculation of the PDCAAS Table: Factors for converting total nitrogen to protein Table: True Protein Digestibility values NUMBER OF GUIDELINE 1 2 METHOD OF DETERMINING THE FAT CONTENT OF FOODSTUFFS DIETARY CARBOHYDRATES • • • • • Classification Methods of analysis Methods of analysis List of hidden allergens Allergen control policy guidelines 5 4 3 Dietary Fiber HIDDEN ALLERGENS QUANTITATIVE INGREDIENT DECLARATION (QUID) GLYCAEMIC INDEX AND GLYCAEMIC LOAD • • Standard operating procedure for the determining of the Glycaemic Index (GI) Formula to calculate the Glycaemic Load GL) EVALUATION OF BACTERIA AS PROBIOTICS FOR USE IN FOODSTUFFS AND NUTRITIONAL SUPPLEMENTS and METHODS FOR THE DETERMINATION OF THE NUMBER OF 6 7 1 VIABLE COLONY-FORMING UNITS IN FOODSTUFFS AND NUTRITIONAL SUPPLEMENTS LIST OF APPROVED FUNCTION CLAIMS LIST OF CATEGORY NAMES UNDER THE AGRICULTURAL PRODUCTS STANDARDS ACT, 1990 (ACT 119 OF 1990) AND THE STANDARDS ACT, 1993 (ACT 29 OF 1993) IN WHICH THE WORD “REDUCED” OR “LIGHT” OR OTHER COMPARATIVE WORD APPEARS, WHICH IS NOT REGARDED AS A COMPARATIVE CLAIM SAMPLING GUIDELINES FOR THE PURPOSE OF GENERATING NUTRITION DATA BY ANALYSIS AND VERIFICATION PRODUCT INFORMATION IN TERMS OF INGREDIENT/ADDITIVES TRACEABILITY • 2 examples of Supplier Ingredient Information Files GUIDELINES FOR THE MANNER OF EXPRESSION OF ENERGY, NUTRIENT OR OTHER SUBSTANCES VALUES, FOUND IN THE TABLE WITH NUTRITIONAL INFORMATION OF FOODSTUFFS OR NUTRITIONAL SUPPLEMENTS GUIDELINES FOR PREPARING DOSSIERS TO SUBSTANTIATE HEALTH CLAIMS FOR PRE-MARKET APPROVAL BY THE DEPARTMENT 13 12 11 10 9 8 2 GUIDELINE 1 WHO DIETARY AND HEALTH GOALS The WHO’s recommendations on diet and health are as follows: Ranges of population nutrient intake goals Total fat Saturated fatty acids (SFA) PUFAs n-6 PUFAs n-3 PUFAs Trans fatty acids MUFAs Total carbohydrate Free sugars* Protein Cholesterol Sodium chloride (sodium) Total Dietary Fiber Non-starch polysaccharides (NSP) Fruits and vegetables 15-30% energy <10% energy 6-10% energy 5-8% energy 1-2% energy <1% energy By difference 55 to 75% <10% energy 10-15% energy < 300 mg/day < 5 g/day (<2 g /day) >25 g/day >20 g/day ≥ 400 g/day Goals for physical activity A total of one hour per day on most days of the week of moderate-intensity activity. is needed to maintain a healthy body weight. Population (adult) mean of 21-23 kg/m 2 For individuals: 2 18.9 kg/m and avoid weight gain of > Goals for body mass index (BMI) BMI 5 kg during adult life *Free sugars means all mono. particularly for people with sedentary occupations. such as walking.5 – 24.and disaccharides added at any point in the processing of food 3 . The food’s essential amino acid profile.25 shall be used to determine the protein content. true digestibility values for estimating PDCAAS.00 in the Protein Quality Evaluation Report of the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation. The food’s true digestibility. pp 74 – 77**. 1990* and the method described in Food Technology. The following requirements summarize the calculation of the PDCAAS of a food protein: 1. may be used. section 9 in the “Protein Quality Evaluation Report of the Joint FAO/WHO Expert Consultation on Protein Quality Evaluation. Rome. in the case where a food contains more than one protein source. Where a food contains more than one protein source. published PDCAAS values. listed in the Guidelines. The food’s protein content. published.”. which manufacturers may use to calculate the PDCAAS of foodstuffs. determined by typical analytical procedures or high performance liquid chromatography (HPLC). the values could be of assi stance in implementing the PDCAAS method. as listed in the Guidelines. 2. References * and *** shall be used. 3. shall be used. usually calculated using the factor 6. Where a foodstuff contains only one protein source. 1990* may be used. 1984).00. 4 . April 1994. listed in Table II. the factor 6.GUIDELINE 2 METHODS OF ANALYSIS (1) METHOD OF DETERMINING NET PROTEIN DIGESTIBILI TYCORRECTED AMINO ACID SCORE (PDCAAS) The protein digestibility-corrected amino acid score (PDCAAS) of a foodstuff is determined in accordance with to the methods described in sections 5.1.25 [or specific AOAC factor listed in the Guidelines. The amino acid scoring pattern described in section 8. For labelling purposes. Department provides a limited database on published true digestibility values (determined using humans and rats) of commonly used foods and food ingredients. the specific AOAC factor. The Department recognises that a database on digestibility Therefore. and in reducing the expense of implementing this new methodology by eliminating the need for a bioassay.4. Rome. and where a foodstuff contains only one protein source. multiplied by the nitrogen (N) content of the food as determined by the AOAC method of analysis (AOAC. and 8. and Compile EEA profile of each protein source from MRC or other recognised international food composition tables and convert data to express EEA values in mg/g protein. How to calculate the PDCAAS of a food protein: Analyse for proximate nitrogen (N) of test product. Analyse for essential amino acid (EAA) profile or calculate EEA profile as follows: Identify protein sources and calculate protein contribution per each protein source of test product. The reference protein* contains (per 1g protein): Histidine Isoleucine Leucine Lysine Methionine plus cystine Phenylalanine plus tyrosine Threonine Tryptophan Valine years) 19 28 66 58 25 63 34 11 35 mg mg mg mg mg mg mg mg mg *1985 FAO/WHO/UNU suggested pattern of amino acids requirements for preschool children (2-5 5 . Calculate protein content (N x 6.25 or specific AOAC factor). Calculate the PDCAAS: PDCAAS = Lowest uncorrected amino acid score x protein digestibility.6 Calculate protein digestibility of test product.5 4. 4.4. Determine the amino acid score (uncorrected) Uncorrected amino = mg of EAA in 1 g of test protein Acid score mg of EAA in 1 g reference protein* Reference protein* EAA profile = 1985 FAO/WHO 2 to 5 year old requirement pattern. 623 0.53 100.71 6.228 0.000 17.290 100.70 1.133 4.418 5.874 7.79 2.000 2.000 5.418 66.897 1.337 1.194 Protein = Nitrogen (N) x AOAC factor for mixed protein sources = 2.824 A Values from product recipe B Values = (A-value/Total recipe mass) x 100 C Values from food composition tables D Values = (B-value/100) x C-value E Values = (D-value/Total formula mass) x 100 F Values = (E-value/100) x Product protein content G Values = Summation per source group A (%) B Ingred Protein C Content Profile Formulation (%) E D Test Product (g/100g) F G Explanatory Notes (g/100g) (g/100g) 6 .347 37.962 1.137 13.753 8.196 0.71 g/100g bread Step 2(a): Identify protein sources of test product and calculate protein contribution of each Source Profile Recipe (kg) Protein Sources White bread Wheat: flour Gluten Soya: Cuts (Grits) Flour Concentrate Linseed Total 119.667 20.71 1.06 0.0 40.0 70.670 0.5.137 13. made w ith mixed protein sources Step 1: Analyse for total nitrogen (N) and calculate protein content of test product Analysed nitrogen (N) content of soy-and-linseed bread: 2.0 17.80 9.217 1.318 1.5 7.12 19.00 11.114 38.25 = 13.596 5. Example: Calculation of the PDCAAS of soy-and-linseed bread.5 78.749 5.0 40.000 178.000 34.581 9.000 1.194 x 6. 927 68.914 52.428 2.931 1.311 0.258 10.097 0.022 60. 1 g wheat protein contains: = (1/8.167 0.360 20.2) x 0.902 (g/100g) (mg/g Prt) 1.989 48.538 49.675 2.484 66.167 g histidine = 0.537 75.022 36.812 2.2 (mg/g (g/100g) Prt) 0.075 Explanatory Notes Example: 8.5 (mg/g Prt) 20.255 2.020366 g histidine per 1 g wheat protein = 20.366 mg histidine per 1g wheat protein 7 .978 66.2 g wheat protein contains 0.854 27.935 (g/100g) 0.796 37.756 38.724 Soya (g/100g) 46.622 0.366 37.316 0.502 1.462 14.118 0.602 13.285 0.839 32.5 Linseed (g/100g) 46.021 0.473 49.789 3.167g histidine Therefore.Step 2(b) Obtain EAA profile of each protein source from food composition tables and express values in mg/g protein EEA Profile of Protein Sources Wheat Composition Protein Essential Amino Acids: Histidine Isoleucine Leucine Lysine Methionine & Cystine Phenylalanine & Tyrosine Threonine Tryptophan Valine (g/100g) 8.419 21.215 43.022 3.683 14.538 81.558 0.108 1.500 0.227 0.322 26.390 43.647 2.676 2.049 34.298 1.257 3. 796 37.015 Content2 1.683 14.225 83.Step 3: Calculate EAA content and uncorrected EAA score of test product EEA Content of Test Product Wheat Composition Protein content (from step 2) 5.538 49.167 491.956 68.749 Profile 1 (mg/g Prt) 26.328 98.075 (mg/100g) 22.g.198 634.935 (mg/100g) 182.688 Content2 6. Uncorrected EEA Score of Test Product = (mg EAA in 1 g test protein) / (mg EEA in 1 g reference protein) 1.155 (mg/100g) (mg/g Prt) 323. Histidine from wheat source = 20.009 708.390 43.332 870.824 Profile 1 (mg/g Essential Amino Acids: Histidine Isoleucine Leucine Lysine Methionine & Cystine Phenylalanine & Tyrosine Threonine Tryptophan Valine Prt) 20.0 51.462 14.054 1.002 1.049 34. EEA profile in mg/g of source protein as determined in step 2(b) e.611 mg/100g 2.758 56.535 1.902 (mg/100g) 118.420 224.3 (mg/g Protein) Score 3 19 28 66 58 25 63 34 11 35 1.423 1015.288 1.890 1.242 1.71 Content2 Profile1 EEA Content Uncorrected EEA (g/100g) Soya (g/100g) Linseed (g/100g) Total (g/100g) Ref Protein Test Product 1.122 0.6 25.007 1.538 81.764 40.g.107 343.537 75.5 35.6/19 = 3.022 36.242 8 . EEA content per amount of source protein in 100 g of test product bread e.6 43.022 60.2 46.996 36.190 24.484 66.905 352.114 337.473 49.935 449.824 = 118.258 10.886 396.8 14.772 161.990 75.230 194.0 63.809 255.580 549.978 66.275 42.150 327.316 202.215 43.857 23.399 293.989 48.839 32.137 Profile 1 (mg/g Prt) 20. Histidine Score = 23.366 x 5.756 38.437 441.419 21.526 589.323 Content2 13.602 13.611 220.854 27.498 93.0 74.366 37.927 68.914 52.677 12. 260 34.374 = 83.753 8.133 4.”.265 7.374 A Values from protein content profile of test product as determined in step 1 B Values from the Guidelines C Values = (A-value/100) x B-value A True Protein Digest Value B Test Protein Digest (%) C Explanatory Notes Step 6: Calculate protein digestibility corrected amino acid score (PDCAAS) of test product PDCAAS = Lowest uncorrected amino acid score of test product x Protein digestibility of test product: References: * ** *** Protein Quality Eval uati on R eport of the Joint FAO/WHO Expert Cons ultati on on Protein Quality Evaluation. FAO Food and Nutrition Paper N o. Geneva.897 1.347 37. Food T echnolog y.Step 4: Calculate protein digestibility of test product Protein Content Profile (%) Protein Sources White bread Wheat: Soya: flour Gluten Cuts (Grits) Flour Concentrate Linseed Totals 38.486 1. World Health Organization.989 4.000 97 98 91 84 95 85 36.581 9. April 1994. 0. No. WHO T ech. Rome.328 9. Switzerland (1985).290 100.150 9 . Ser.046 93. Energy & Protein Requirements. pp 74 – 77.890 x 93. Joint FAO/WHO/UNU Expert C ons ultation. 51. Protein Quality Eval uati on by Protein Digestibility-Corrected Amino Acid Scoring. Rept. 1990. 724. 31 5.18 5.30 5.74 4.25 6.25 6.38 5.83 6.70 5.37 6.25 5.80 5.38 6.70 5.25 6.83 6.95 5.25 4.32 6.30 6. OATS AND RYE *MILLET *MAIZE CHOCOLATE AND COCOA MUSHROOMS YEAST COMPOUND FOODS (MIXED PROTEINS) 5. *BRAZIL AND GROUNDNUT *OTHERS GELATIN OIL SEEDS CEREALS: *DURUM WHEAT *WHEAT: **WHOLE **BRAN **EMBRYO **ENDOSPERM *RICE *BARLEY.12 6.55 5. POULTRY AND FISH EGGS: *WHOLE *ALBUMIN *VITELLIN MILK AND MILK PRODUCTS CASEIN HUMAN MILK SOYA BEANS NUTS: *ALMOND.40 6.31 6.FACTORS FOR CONVERTING TOTAL NI TROGEN TO PRO TEIN FACTOR MEAT.25 10 .70 6.46 5. cereal Sorghum Triticale Wheat Sorghum. milled. whole 11 . extruded cereal Corn. white Bread. whole wheat Bran Endosperm Flour. 90% extracted Flour. cooked Rice. brown. cooked Triticale Bread Bread. whole Corn. quick oatmeal Rice Rice Rice germ Rice. brown Bread. crisped. flake Corn. coarse. polished Rice. cooked Rice. 80% extracted Wheat germ Gluten Puffed wheat Shredded wheat White flour Wheat. high protein Rice.TRUE PROTEIN DIGESTIBILITY VALUES MAJOR PRODUCT GROUP Cereals and grains: Barley Maize (Corn) Barley PRODUCT TRUE PROTEIN DIGESTIBILITY VALUE 90 62 70 76 89 84 79 70 90 82 91 87 72 85 86 87 77 73 90 96 91 98 92 75 98 89 92 81 98 84 73 97 87 Corn. puffed cereal Corn. meal Millet Oats Millet Oat flakes Oatmeal Oat. frozen Beans. defatted Egg. powdered Whey Egg and egg products: Egg albumin Egg. cereal Wheat. kidney Beans. black Beans. velvet Beans. sugar 68 57 78 69 79 82 71 81 80 73 78 82 81 97 92 93 98 100 96 92 97 Whey protein 95 96 99 99 94 94 94 95 95 12 . common Beans. hot. butter Beans. canned Beans. brown. snap. powdered. dried Egg. flakes Egg. 40% bran flakes 85 69 TRUE PROTEIN DIGESTIBILITY VALUE Dairy Products: Casein Cheese Lactalbumin Milk Acid casein Casein Cheddar Cottage Lactalbumin Skim Whole Whole. spray dried Egg.TRUE PROTEIN DIGESTIBILITY VALUES MAJOR PRODUCT GROUP PRODUCT Wheat. red Beans. spotted. cooked Beans. whole unprocessed Legumes and oilseed products: Beans (Mucunoa Spp) Beans (Phaseolus Lunatus) Beans (Phaseolus Vulgaris) Beans. Natal round yellow Beans. dried Egg. haricot Beans. powdered. scrambled Egg. lima Beans. pinto. speckled Beans. frozen Pea flour Peas (Vigna ungulata) Sesame Soy products Cowpeas Sesame seed. green. white. low fat. raw Chick peas. ground Beef. dehulled Soybean Soy concentrate Soy flour Soy flour. spun Sunflower Meat and meat products: Beef Sunflower seed Sunflower seed flour Beef Beef. faba Cottonseed Cottonseed meal Flaxseed Lentils Lupine Peanut butter Peanut flour Peanuts Peanut meal Peas (Cajanus Cajan) Peas (Cicer Arietinum) Peas (Pisum sativum)_ Pigeon peas Pigeon peas. kidney 69 78 78 87 86 78 80 85 85 76 95 93 87 91 76 41 88 94 88 94 88 79 82 91 95 84 87 96 100 82 90 95 91 97 TRUE PROTEIN DIGESTIBILITY VALUE Beans (Vicia faba) Cottonseed Flaxseed Lentils (Culinaris) Lupins (Lupinus Albus) Peanut products Beans. broad Beans.TRUE PROTEIN DIGESTIBILITY VALUES MAJOR PRODUCT GROUP PRODUCT Beans. canned Pea concentrate Peas Peas. sugar Beans. defatted Soy isolate Soy protein. sugar. defatted 13 . powdered. salami Beef. canned Pork. roasted 98 89 97 91 100 95 90 97 97 94 98 100 92 93 91 94 TRUE PROTEIN DIGESTIBILITY VALUE Fish and seafood: South African hake (haddock) Sardine Tuna. light meat Turkey breast. stew Beef. steak Beef.TRUE PROTEIN DIGESTIBILITY VALUES MAJOR PRODUCT GROUP PRODUCT Beef. canned Luncheon meats: Canned frankfurters Chicken frankfurters Sausage Pork: Poultry: Chicken Chicken. roasted Miscellaneous foods: Nuts and nut products: Cashew Coconut meal. defatted Pecan Starchy roots and tubers: Vegetables: Cabbage Kale Rape Mustard Turnip leaves Mushrooms 88 85 85 82 86 90 Potato 85 80 71 89 Macaroni cheese. loin and tenderloin 14 . tenderloin. dark meat Chicken. 2002. There are also alternative competitive capillary columns on the market.2 Analysis of Trans-fatty acids The definition for trans fats may be the first definition to exclude the two major trans-fatty acids occurring naturally in foods from animal sources that have potential health benefits.Fat (Total.28A) can still be used for extraction and methylation.1. It is widely available and allows identification of individual fatty acids when using suitable standards. and the method is validated and accredited by SANAS or another international accreditation body.1 METHOD OF DETERMINING THE FAT CONTENT OF FOODSTUFFS Total fat The total fat content of a foodstuff is determined in accordance with the method described in the latest edition of “Official Methods of Analysis of the Association of Analytical Chemists” published by the Association of Analytical Chemists of the United States of America. 15 . gas chromatography separates compounds based on their chemical structure and/or functional groups.GUIDELINE 2 (continued) METHODS OF ANALYSIS (2) 2. As with most analytical procedures. Saturated. unless another validated method related to the particular product is used. 17 th Edition. Revision 1. the definition would allow for any trace amounts of these transfatty acids that may be present in industrially formed trans-fats. The only suggested difference is lengthening the capillary column SP-2340T M used to at least 100m to improve resolution between fatty acids allowing for better identification and more accurate quantification. chapter 41. Gas-liquid chromatography is probably the most popular and preferred technique. namely trans-Vaccenic acid and conjugated linoleic acid.06 . which are just as efficient. Due to the fact that the chemical structure of both industrially made and naturally occurring trans-fatty acids are identical. The official “AOAC method 996. 2. However. suitable validation and verification checks should always be performed prior to their use. By not mentioning “from animal origin” within the definition. and Unsaturated) in Foods” (Official Methods of Analysis of AOAC International. it is not possible to differentiate between these two groups. GUIDELINE 3 THE MAJOR DIETARY CARBOHYDRATES CLASS (DP*) SUBGROUP Monosaccharides Sugars (1-2) Disaccharides Polyols Malto-oligosaccharides Oligosaccharides (3-9) Other oligosaccharides Starch Polysaccharides (>9) Non-starch polysaccharides Cellulose. hydrocolloids Raffinose. maltose Sorbitol. hemicellulose. amylopectin Modified starches COMPONENTS (Examples) Glucose. Lactotol Maltodextrins DP* = Degree of polymerisation 16 . stachyose. Fructo-oligosaccharides Amylose. trehalose. fructose Sucrose. lactose. galactose. Pectins. Mannitol. Xylitol. protein. e.and malto-oligosaccharides/maltodextrins. which is considered the gold standard method. polydextrose. starch (amylose. However. ash. slimming. dietary Fiber (non-starch polysaccharides (NSP). and organic acids.GUIDELINE 3 (Continued) THE MAJOR DIETARY CARBOHYDRATES RECOMMENDED METHODS OF ANALYSIS 1. therefore companies and laboratories are encouraged to start implementation of this preferred method as soon as possible. glycogen and sugar alcohols and can be determined either by (a) adding together all the analytical values for all mono-.. alcohol. The Department will allow the less preferable method (b) below for another 3 years after which method (a) will become mandatory. Glycaemic carbohydrate: For purposes of energy evaluation. a standardised. or foods for which a reduced energy content. added resistant starch. all mono-. glycogen and sugar alcohols. raffinose and stachyose). or (b) calculation by difference by subtracting from 100 the average quantity expressed as a percentage of water. Southgate. pyrodextrins. lignin. 17 . di. fructo-oligosaccharides and galacto-oligosaccharides).and malto-oligosaccharides/maltodextrins. di. glycerol.g. amylopectin and modified starch). nondigestible oligo-saccharides. direct analysis of available carbohydrate (by summation of individual carbohydrates) (FAO. 1976) is preferable to an asse ssment of available carbohydrate by difference (total carbohydrate by difference minus dietary Fiber). which is useful in determination of energy values. Direct analysis is considered the only acceptable method for analysis of carbohydrate in functional foods. starch (amylose. 1997. Carbohydrates or glycaemic carbohydrates namely. amylopectin and modified starch). fat. Direct analysis allows separation of individual mono—and disaccharides and starch. it is recognised that this method is expensive. Glycaemic Index value or any other type of carbohydrate claim is made. and they can be affected by food processing or may be added to food. water solubility. Instead. Using this approach. A source element identifying that dietary fibre is an intrinsic component of these food groups. Therefore. but these do not provide a consistent indicator of plant rich diets. which have a DP mostly between 3 and 9. 2. have chemical. there has not been wide-scale use of fibre-like ingredients as supplements. Rationale for defining dietary fibre as 'intrinsic plant cell wall polysaccharides' The established epidemiological support for the health benefits of dietary fibre is based on diets that contain fruits. oligosaccharides and fibre supplements (prebiotics) should be researched and. This approach is preferable to the determination of all the individual parts of plant cell wall material.2. which are derived mainly from these population studies. and by determining this characteristic component it is possible to indicate the presence of other beneficial substances. which have the characteristic of containing plant cell walls. To achieve this aim. if shown to be beneficial to health. A chemical element identifying the component to be measured. 18 . The structural polysaccharides are the major part of plant cell walls. which can be called short chain carbohydrates. To include them within a dietary fibre definition would clearly represent a conflict with reference intake values and health claims. lignin and other substances are not included in the definition. e. the best approach is to validate and if appropriate. vegetables and wholegrain cereal foods. Other carbohydrates share the feature of resisting digestion in the small intestine.g. be promoted in their own right. the definition should include the following: 1. The above definition does not include non digestible oligosaccharides. resistant starch. The inclusion criteria based on the demonstration of specified physiological properties is neither appropriate nor manageable within a dietary fibre definition. intake of which has been used to establish population reference values for dietary fibre. Dietary fiber and prebiotics Definition of dietary fibre The definition of dietary fibre is more clearly linked to fruits. It is this food component that should form the basis of a dietary fibre definition as it provides a consistent indicator of the plant foods promoted in guidelines. This group of carbohydrates. Until recently. dietary fibre is defined as a natural food component and no further criteria are required. vegetables and wholegrain cereals. such as micronutrients and phytochemicals that are present in the plant. and the current epidemiological evidence base for dietary fibre rich foods cannot be extrapolated to diets containing such preparations. Based on the rationale described below the following definition is proposed: ‘Dietary fibre consists of intrinsic plant cell wall polysaccharides'. which is both impractical and would not add to the nutritional message that is provided by focusing on the polysaccharides of the plant cell wall. Considering the variation in chemical and physiological properties involved. establish health claims on an individual basis. physical and physiological properties that are distinct from the polysaccharides of the plant cell wall. This emphasizes that dietary fibre reflects fruits. the Englyst method is a reliable. and their suitability should be asse ssed by how well they measure the defined food component. minerals and not by their alleged functions. 3) suitability as measures of dietary fibre. vegetables and wholegrain cereal foods. 4) the impact their use would have on public health. Non-digestibility cannot be measured in the laboratory. there is no method that can support such a definition. it was felt that the emphasis should be on the role of dietary fibre reflecting a natural plant-rich. the NSP and AOAC gravimetric approaches were compared. Therefore. The Englyst method. non starch polysaccharides. Dietary fibre defined as 'intrinsic plant cell wall polysaccharides' includes the phrase “intrinsic". e. oligosaccharides. whole food diet. Most nutrients and food components are defined and measured as chemical substances. each of these various carbohydrates has distinct properties other than non-digestibility. protein. Furthermore. fruits and vegetables. Defining dietary fibre as 'intrinsic plant cell wall polysaccharides' provides the analyst with a clear objective and the method or choice of methods should be those that most accurately and reproducibly identify and measure these polysaccharides. enzymic or chemical means” or “synthetic carbohydrate polymers” were not included. The “carbohydrate polymers which have been obtained from food raw materials by physical. hitherto. “Digestibility” has a very different connotation when used to describe the digestible energy of foods. Although there is no formally agreed international definition of digestibility for humans in the field of energy values of food. which should be measured separately. This comparison clearly identifies the strengths and limitations of the two main approaches to the measurement of dietary fibre. However. Digestion should be seen as an integrated whole gut process. because. accurate and specific 19 . Patterns of carbohydrate digestibility in the human gut can vary not only amongst different carbohydrates. Non-digestibility in the small intestine groups together a wide variety of carbohydrates that includes polyols.g. “digestibility is defined as the proportion of combustible energy that is absorbed over the entire length of the gastrointestinal tract”. fat. therefore. again. been considered to be part of dietary fibre.organoleptic properties. They have not. Both the Englyst and the AOAC methodologies are recognised as acceptable methods of analysis. some starch. and 6) nutrition research. As part of the scientific update on the issues related to measuring dietary fibre. and in many populations. 5) food processing. Other sources of non glycaemic carbohydrates would best be served by individual health claims that take into account their specific efficacy and dosage issues. which should be measured and exploited separately from dietary fibre for their own benefits to health. effects on the gut microflora (prebiotic). immune function and calcium absorption making them a unique group of carbohydrates. The comparison addresses: 1) general principles of the procedures. 2) practical methodological issues. vitamins. the term “digestibility” is probably best reserved for total digestion and absorption from the whole gut. lactose. Methods of analysis Methods of analysis are a secondary issue. as summarized in Table 2 below. is the preferred method of choice. but also from person to person and. This detracts from the essential role of dietary fibre as plant cell wall carbohydrate found in wholegrain cereals. .15 Enzymatic 32 Lee et al Enzymaticgravimetric 32. The NSP procedure as the most suitable in respect of performance and suitability as a measure of dietary fibre. 2002 Prosky et al.2000 Hoebregs.06B Theander et al.4. 1992 Enzymatic gravimetric 45.13 Soluble & insoluble polysaccharides (including RS 3) & lignin) AOAC 999.07 Enzymatic 45.4. inulin derivatives.4. inulin derivatives. Enzymatic chemical 45.11 Beta-glucans McCleary & Codd.method of analysis for non-starch polysaccharides (NSP). However.4.08 Fructans (oligofructans.03 Fructans (oligofructans.06A Enzymatic & colorimetric 45..02 AOAC Trans-galactooligosaccharides Total dietary Fiber in Enzymatic and 45.13 De Slegte HPAEC-PAD 45. whereas the AOAC method is not. 1997 Enzymatic & HPAEC 45.4.1.4. 1991 McCleary & Monoghan.16 AOAC 200202 AOAC 985. fructooligosaccharides) AOAC 997. fructooligosaccharides AOAC 2001. 1999 McCleary et al.4. METHOD Englyst method (method of preference) AOAC 991.43 Soluble + insoluble polysaccharides (including RS 3) and lignin AOAC 995.29 Resistant starch and algal Fiber Soluble & insoluble polysaccharides (including RS 3) & lignin) AOAC 994.12 McCleary & Blakeney. the NSP methods is the method of choice for infant formula.17 QUANTIFIED COMPOUNDS Non-starch polysaccharides TABLE 1 REFERENCE TYPE CHAPTER* 20 . dietary fibre may include fractions of lignin and/or other compounds when associated with polysaccharides in the plant cell walls and if these compounds are quantified by the AOAC gravimetric analytical method for dietary fibre analysis : Fractions of lignin and the other compounds (proteic fractions. The AOAC 991. these associated substances may provide additional beneficial effects. FOS) nor resistant starch3 fractions RS1 and RS2 which are not measured by these AOAC method. When derived from a plant origin.43 method. The methods for total or soluble+insoluble dietary fibre give satisfactory results for foods that contain neither added non-digestible oligosaccharides (e. when extracted or even re-introduced into a food containing non digestible polysaccharides. they cannot be defined as dietary fibre. The other methods can be used for complementary asse ssment of other fibre components/fractions not measured by the general methods due to their solubility in aqueous alcohol or for analysis of certain foods or raw materials for which the standard methods may be less suitable. certain types of raw starch granules (RS2) and retrograded amylose (RS3). 21 1. However.43 are the general methods for measuring ‘total dietary fibre’ in most foods. The AOAC 985.. When combined with polysaccharides.03 foods containing resistant maltodextrin gravimetric & Liquid chromato graphy AOAC 2000.) intimately "associated" with plant polysaccharides are often extracted with the polysaccharides in the AOAC 991. It consists of physically enclosed starch (RS1). cutin. 17th edition. These substances are included in the definition of fibre insofar as they are actually associated with the poly. phenolic compounds. RS3).2001. These methods have the advantage of being used worldwide as well as being easily used in routine analysis. GENERAL PRINCIPLES Stated Aim .06C Official Methods of Analysis of AOAC International. Modified starches used as food additives may also be partially resistant (RS4). Therefore.g. 2001 HPAEC 45.6.29 and 991.43 includes part of the resistant starch fractions (retrograded starches. in order to include total RS.or oligo-saccharidic fraction of fibre. etc. Editor Horwitz All the above methods are approved AOAC techniques. TABLE 2: COMPARISON OF THE NSP AND THE GRAVIMETRIC AOAC METHODS WITH RESPECT TO PERFORMANCE AND SUITABILI TY AS A MEASURE OF DIETARY FIBRE 10 NSP procedure 8 To measure polysaccharides that do not contain the alpha 14 glucosidic linkages Grav imetric AOAC procedure 9 To measure the sum of indigestible polysaccharides and lignin. saponins. Resistant starch (RS) is defined as the fraction of starch not absorbed in the small intestine. waxes. phytates. phytosterols. Volume II.11 • Polydextrose Craig et al. it is necessary to analyse RS independently and correct for the RS in the fibre residue. pullulanase (EC 3. Batch sizes are limited by the 22 Effect of Food Processing Is Stated Aim Achieved Yes.2. amyloglucosidase (EC 3.1. The procedure completely removes starch and sugars and provides a specific determination of NSP. NSP is minimally affected by normal food processing.1. pectinase (EC 3. the non carbohydrate part can include food processing artefacts.1.g. Hydrolyse and measure NSP as sum of constituent sugars by either colorimetry or chromatography (GC). Analysis vessels: screw cap test tubes. soluble and insoluble residue containing carbohydrate and noncarbohydrate material in unknown proportions. A range of materials are recovered in the residue. with the option of detailed information on constituent sugars by the GC version. Analytical Principle Complete dispersion and enzymatic hydrolysis of starch.15). (EC 3.2. protease.1). (EC 3.characteristic of starch (i.2. this procedure measures a variable amount of resistant starch. pancreatin (these enzymes should be devoid of NSP hydrolytic activities). METHODOLOGY 30.1. In addition to lignin.1). which is highly dependent on food processing (e. non starch polysaccharides). Analysis vessels: 400 ml beakers and fritted glass crucibles.e. muffle furnace and Kjeldahl equipment.1). not consistently. Equipment: Vacuum manifold. retrograded starch. soluble and insoluble NSP.2. Information Prov ided Values for total. Weight of total. Specific Reagents And Equipment Practical Issues All the steps of this procedure . Record total residue weight and then determine and subtract ash and protein contents.1. These enzymes should be devoid of NSP hydrolytic activities. Partial enzymatic hydrolysis of starch and protein. No. 11. As a chemically distinct food component.41).2.12 NSP procedure 8 Enzymes: Heat stable amylase. Malliard reaction products). Equipment: Centrifuge and either spectrophotometer or GC system. In addition to NSP. 2. which may not relate to the true extent of physiological starch digestion. Grav imetric AOAC procedure 9 Enzymes: Heat stable amylase. Precipitate residue in 80% ethanol and isolate by centrifugation. Precipitate residue in 80% ethanol and isolate by filtration. 26.5-2 days or more with longer filtration times. Large amounts of solvent waste are generated. There are numerous versions of this definition. Env ironmental Impact Only small amounts of solvent waste generated. The primary standard is a representative mixture of the individual monosaccharides of NSP. No primary standard is available as the procedure does not measure a chemically distinct component. which mainly consist of Indigestible carbohydrate (DP >3) and lignin. The method CV is less than 5%.5 days for the GC measure.g. sugars. The method CV is less than 5%. with no interference from other substances. The gravimetric procedure requires specialist glassware. This definition is targeted specifically at the fruits. The selective removal of starch other than RS is difficult or impossible to achieve within this procedure. which makes it well suited to the analysis of large batch sizes. Suitability For Use In Dev eloping Countries Traceability Method Specificity Method Reproducibility 3. A range of certified reference materials are available (e. numerous pH checks. vegetables and whole grain products that are consistently linked with health benefits. which is achieved by a combination of physical. subsidiary ash and Kjeldahl methods.are conducted in test tubes. Any added material or food processing artefacts recovered in the residue are a potential source of interference. The NSP procedure only requires standard laboratory equipment including a spectrophotometer for the colorimetric version.16. The chemical end-point determination techniques are the same as those used in the measurement of other carbohydrates (e. These foods have the characteristic feature of containing plant cell walls. manual transfer and filtration of residues. BCR). BCR).g. starch). muffle furnace and Kjeldahl equipment for the measurement of nitrogen. Only NSP is measured. difficulties of handling large numbers of 400 ml beakers.7. chemical and enzymatic steps. The method is labour intensive due to: preparation and repeated weighing of the crucibles. The procedure takes 1.g. It is important to ensure complete starch dispersion and hydrolysis. The procedure takes 1 day with the colorimetric measure or 1. DETERMINATION OF 6. The definition is not restricted to carbohydrates as it encompasse s lignin and other substances associated with the 23 . 13 DIETARY FIBRE Associated Definition and Measurement Task Definition Rationale Intrinsic plant cell wall polysaccharides. which have the common feature of placing the emphasis on escaping digestion in the small intestine. A range of certified reference materials are available (e. 24 Potential discrepancies between definitions and determinations For plant foods. This distinction allows the properties of other non glycaemic carbohydrates to be researched and if appropriate promoted in their own right. In a few plants NSP can occur as gums and alginates. The residual starch recovered can be misleading. but rather the effect of synergistic elements including micronutrients. When extracted or synthesized NSP are present in products then these will be known by the manufacturer and can be deducted from the NSP measurement to obtain a value for the intrinsic plant cell wall polysaccharides. vegetables and whole grain products. as it does not relate to physiologically resistant starch. It can include noncarbohydrate food processing artifacts (e. Maillard reaction products) that are not part of any dietary fibre definition. However. Retaining a distinct dietary fibre term identifying plant rich diets with their unique health benefits reinforces the food based dietary guidelines. Other non-carbohydrate components are not included as they can neither be determined specifically nor would their inclusion enhance the definition as an indicator of these foods. The definition is focused on this carbohydrate component.g. as supplementation with other types of non glycaemic carbohydrate preparations was uncommon. The presence of specific extracts can often be identified by their NSP . for which separate measurement is required.structural polysaccharides. plant cell wall. as this grouping can include a wide range of substances it has been suggested that there should also be a demonstrated physiological effect for a specific material to be included. The long term health effects/safety remain to be established. For the existing epidemiological evidence relating to the last few decades this definition provides a reasonable indicator of plant rich diets. However. In addition to the plant cell wall polysaccharides. the indigestibility criterion has the implication of including resistant starch and other extracted or synthesized carbohydrates. which is strongly supported by the epidemiological evidence for the health benefits of fruits. but these are not typical foods and are more likely to occur as ingredient extracts. but these vary depending on type. As the AOAC gravimetric procedure measures a range of indigestible materials of varied composition and origin it does not provide a consistent measure of plant cell wall material. this is not always the case for individual manufactured products. the NSP content is a measure of ‘i ntrinsic plant cell wall polysaccharides’. Scientific Evidence For Rationale This is a food based rationale. including nondigestible oligosaccharides. making it difficult to consider them within a single definition. phytochemicals and low energy density. The definition recognises that the benefits of a natural fibre rich diet are not due to any single component. which can be quantified in chemical terms. Specific physiological properties have been associated with individual supplements. It does not recover non digestible oligosaccharides. and therefore by itself does not provide a measure of the indigestible carbohydrates proposed for inclusion. The NSP procedure provides measurements that are suitable for this definition. Neither does the AOAC gravimetric procedure provide a consistent measurement of the material included in this definition. It is inappropriate to apply the epidemiological evidence as a basis for health claims in combination with a definition that includes AOAC gravimetric values of unknown composition. and in some cases includes food processing artefacts. specific health claims should be established for individual non glycaemic carbohydrate supplements. By grouping all indigestible carbohydrates within a single undifferentiated nutrition label. resistant maltodextrins or all resistant starch. which tend to have specific functional properties. which would undermine the position of dietary fibre as a beneficial food component. The labelling with AOAC gravimetric values has the potential to mislead consumers. non digestible oligosaccharides and RS are separate groupings. There substances require separate analysis if they are to be included.Suitability as a measure of dietary fibre constituent sugar profile. IMPACT ON PUBLIC HEALTH 6. then there would be scope for these to be labelled specifically. thereby acknowledging their specific functional properties and taking account of variations in their effective and safe dosages.33 Nutrition Labelling A dietary fibre value describing intrinsic plant cell wall polysaccharides would guide consumers to the selection of plant rich foods.26. The indigestible carbohydrate and lignin definition does not consistently identify plant rich diets. When appropriate. as the material measured is not a consistent indicator of plant rich foods. With the plant cell wall polysaccharide definition.16. There is the potential for inappropriate health claims for materials with either no effect or detrimental properties. which relates to fibre from plant rich diets. If other sources of non glycaemic carbohydrates are present.7. as well as a range of supplemented materials with varied functional properties. there is less opportunity to identify any supplements present. The use of this definition could result in a situation where the consumer selects supplemented products on the 25 Health Claims The health claims for dietary fibre are largely based on the epidemiological evidence. The intrinsic plant cell wall polysaccharide definition provides a clear link to the plant rich diet shown to be beneficial to health. Population Reference Intakes The population reference intake values for dietary fibre are largely based on the epidemiological evidence that . 4. Their content in foods is measured specifically and they do not conflict with the NSP measurement. minimally refined plant rich diets are associated with a lower incidence of several diseases. supplements and noncarbohydrate artefacts in 26 5. Values can consist of plant cell wall material. 1) that the supplemented product is unjustly promoted on the back of the epidemiological evidence. IMPACT ON NUTRI TION RESEARCH Food composition data has a crucial role in nutrition research. IMPACT ON FOOD INDUSTRY Although NSP values are generally lower than those for the gravimetric procedure. food labelling cannot be based on food table values of component ingredients. retrograded starch. basis that they will contribute towards the reference intake value. this should not make a difference to the marketing of the majority of products. Neither does the procedure provide any details of what has been measured. there would be significant cost savings with the analysis of NSP compared to the AOAC gravimetric analysis. As gravimetric values are influenced by food processing. However. as it would be possible to elevate the dietary fibre content through processing or supplementation instead. This may be perceived as conflicting with the intended aim of reference intake values and dietary guidelines which are targeted at plant rich diets. there would be less impetus for the manufacturer to incorporate unrefined plant ingredients. it would be difficult for the consumer to distinguish between these different types of product if they carried identical health claims. With this definition. and 2) that if direct substitution of products occurs. As the AOAC gravimetric procedure does not measure a specified food component it does not provide the precise and informative data required for nutrition research. 6. The intrinsic plant cell wall polysaccharide definition ensures that dietary fibre intakes contributing towards the reference value would consistently reflect both the epidemiological evidence and the intended message of the dietary guidelines. For food labelling purposes. There would be a positive opportunity to market other types of non glycaemic carbohydrates with respect to their specific functional properties. Grouping the varied supplements together limits the opportunities for manufacturers to promote the specific functional properties of individual products. as population reference intakes and health claims would be established on the same basis. although in reality this would not be a true reflection of the intention of the dietary guidelines. The emphasis would be on manufacturers to incorporate minimally refined plant ingredients into products to achieve health claims for dietary fibre. This raises two concerns. The intrinsic plant cell wall polysaccharide definition provides a firm link with the minimally refined plant rich diet consistently associated with health benefits. then the consumption of the intended target food groups may be diminished. as only with precise and informative descriptions is it possible to address the mechanisms responsible for the relation between diet and health. This food . H. (1996). Measurement by the AOAC procedure. The method specific certification of the mass fraction of dietary fibre in lyophilised haricot beans. Englyst.N. apple. Cummings JH (1993). Dietary Fibre. Quigley.45. full fat soya flour and bran breakfast cereal reference materials. USDA/DHHS.J. HN. & Brookes. Quigley. Nutrition research is better served by detailed information on specific food components. H. 1-52. Englyst. USA 3. Measurement by the Englyst NSP procedure. DAT. 1-52. L. It does not provide a consistent indicator of plant rich diets. Wood. K.component can be described in chemical terms. at best it provides a crude tool for nutrition research. Dietary Fibre. carrot. Quigley M E. Only with detailed information on distinct substances will it be possible for future epidemiological studies to establish the intakes and effects of different types of non glycaemic carbohydrates. (1996). Journal of the Association of Public Analysts.N. (1996). R. Analyst. 119. N.29 and 991. M. MD. R. 32. Hudson G J. Office for Official Publications of the European Communities. M. 119. Determination of dietary fibre in foods collaborative trials. A. including an indication of the types of polysaccharides present from their constituent sugar composition. 515. but not all resistant starch or nondigestible oligosaccharides. Official methods of analysis 17th Ed W Horwitz. G. Explanation of the differences. Comparison of the NSP and the grav imetric AOAC methods w ith respect to performance and sustainability as a measure of dietary fibre 1. (2005) Nutrition and your health: dietary guidelines for Americans. 9. Official methods of analysis 17th Ed W Horwitz. High-performance Liquid Chromatographic or Spectrophotometric Measurement of Constituent Sugars’. Englyst. CL 2007/3-CCNFSDU page 13 11.. Englyst. 516.W. IV. Bravo.45. Luxembourg 6. & Hudson.E. High-performance Liquid Chromatographic or Spectrophotometric Measurement of Constituent Sugars. Washington. AOAC International. IV.. L. but also encourages specific research into other types of non glycaemic carbohydrates. Journal of the Association of Public Analysts. Englyst H N. CRMs 514. Hudson G J. DAT. Gaithersburg. Analyst. Englyst. 57-141. CL 2007/3-CCNFSDU page 12 8. Explanation of the differences. 2. A definition based on the gravimetric method and indigestible carbohydrates within a single undifferentiated grouping will not provide the detailed information required by future epidemiology studies to establish the intakes and health effects of different types of non glycaemic carbohydrates. The emphasis is on providing a nutritional approach to the description of the carbohydrate composition of foods. 4. K. 1497–1509.N. Journal of the Association of Public Analysts. 32. (1994) Determination of Dietary Fiber as Non-starch Polysaccharides with Gas–Liquid Chromatographic. 1497–1509. Englyst. Gaithersburg. Measurement by the Englyst NSP procedure. AOAC International..E.. 29. Maintaining this distinct definition of dietary fibre not only facilitates research into the benefits of plant rich diets. Quigley M E. G. & Hudson. Bravo. Measurement by the AOAC procedure.. Meuree-Vanlaethem. Therefore. Pendlington. Comparison of Englyst GLC and colorimetric measurement with the Prosky procedure.. HN. (1994) ‘Determination of Dietary Fiber as Non-starch Polysaccharides with Gas–Liquid Chromatographic. Cummings JH (1993).29 and 991. Southgate. 5... Comparison of Englyst GLC and colorimetric 27 . unknown proportions.J. AOAC (2000) Methods 985.N. A.. Determination of dietary fibre in foods collaborative trials. but one that is prone to confound the interpretation of results. AOAC (2000) Methods 985. MD. USA 10. Englyst H N. DC. providing the means with which to explore functional properties. Nor is it a reliable measure of indigestible carbohydrates as it includes non-carbohydrate components. Southgate. Wood. 517 & 518. Kuo. DC.75:395-416. Greenfield H. H. A.W.T. 29. Determination of food carbohydrates. A. D. References: Carbohydrates in Human Nutrition (1997): Report of a Joint FAO/WHO Expert Consultation.measurement with the Prosky procedure. & Brookes. 3 – 6 December 2002. Southgate.T. 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Journal of the Association of Public Analysts. Y. CRMs 514. References to methods in the table: AOAC 985. J Assoc Off Anal Chem 1985. 1976. Rome. (1996).. 39: 223-7. Harland B. H. lamb and veal offal. 12.29: Prosky L. Schweizer TF.A.78:10301044. Food Technol. Beef. Westerlund E. 4. AOAC 991. full fat soya flour and bran breakfast cereal reference materials. Luxembourg CL 2007/3-CCNFSDU page 14 13. Total dietary Fiber determination as neutral sugar resides. Report of a technical workshop. Washington. & Greenfield.L.68:677-679. J AOAC Int 1992. Food energy – Methods of Analysis and Conversion Factors. De Vries J. Enzymatic gravimetric method. 515.