1.Banana Ripening Process Ripening is the process by which fruits attain their desirable flavour, quality,colour, palatable nature and other textural properties. Ripening is associated with changein composition i.e conversion of starch to sugar. On the basis of ripening behavior, fruitsare classified as climacteric and non-climacteric fruits. Banana is one of the climacteric type which is defined as fruits that enter ‘climacteric phase’ after harvest they continue to ripen. During the ripening process the fruits emit ethylene along with increased rate of respiration. Ripe fruits are soft and delicate and generally cannot withstand rigours of transport and repeated handling. These fruits are harvested hard and green, but fully mature and are ripened near consumption areas. Small dose of ethylene is used to induce ripening process under controlled conditions of temperature and humidity. During ripening, bananas release small amounts of ethylene, volatile esters and carbon dioxide. It is important that these gases be confined to the ripening room particularly during the early stages of the process. The amount of gases present has a direct bearing on the rate of ripening at a given temperature. To best control the speed of ripening, it is essential to apply ethylene artificially. The ripening process for bananas is typically as follows: 1) Green bananas in cartons or open crates are loaded into the ripening room (fruit pulp temperature should not be lower than 14 ºC as lower temperatures can damage the fruit). 2) The room is closed and thermally controlled until the pulp temperature reaches 15- 17 oC. This temperature is controlled and maintained by a thermostat. During summer conditions or for direct field produce, a refrigeration system will cool the room to maintain the set temperature and remove the heat of respiration. 3) Ethylene is supplied into the room at a concentration of around 100-400ppm (0.01 0.04%). The room is then kept closed for 24 hours. The ethylene acts as a catalyst initiating the hormonal process of ripening. 4) At the end of this time the room is ventilated to clear the ethylene gas and the carbon dioxide released due to increased respiration during the initial ripening phase. banana would change it colour. Further explanation as follows : a. are evolved in substantial quantities. Method of introducing ethylene gas : Ethylene generators which use a catalytic process to produce pure ethylene gas from a solution containing mainly ethyl alcohol (ethanol) but which may have trace quantities of other ingredients (e. pectin content . The main changes is a change in water content . Extractor fans may also be used. The fruit pulp may reach a temperature of 32oC during this process and gases. as carbon dioxide levels above 7% inhibits further ripening. This kind of substance are derivative of poligalacturonate acid and contained in protopectin . A common way of ventilating involves opening the doors for at least five. methanol). and smell which is indicates the change of their characeristic.5) The room temperature is controlled between 17oC to 15oC over three or four days. acidity .e. and tannin content . the amount of ethylene required is calculated for the remaining 65% free air space. minutes before entry is made. The changes of flesh and peel condition The ripening process of banana is signed with the soft flesh of the fruit . from green then turn into yellow and begin to increase the amount ethylene gas. the content ofsoluble pectat and pectinate is gradually increased . The amount of ethylene gas required for a ripening room is normally calculated on the free air space after the bananas have been loaded (i. respiration rate .g. pectin . The solution (sometimes known as 'ripening fluid') is poured into a reservoir on the ethylene generator where it is slowly fed to an internal heater which vaporises the ethanol which then passes to the catalytic converter. texture . 6) The room is finally ventilated and the ripe fruit removed. When fruit becomes ripe . Each litre of solution produces about 0. protopectin content. Most of these gases would normally be vented off by ripening room operators to maintain the carbon dioxide level below 1%. carbohydrates content. and usually fifteen.4 m3 of ethylene gas. including carbon dioxide. pectinate acid and other concentrated acid ( Kerteaz . while the pectant content is entirely . During the process of ripening. Palmer (1971) said that the maturity indicator of banana is the change of peel colour. It is caused by an overhaul protopectin which is insoluble by becoming soluble pectin. if bananas take up 35% of the room size. 1951) .33-0. The acidic content of isobutyrate . butyric and free isovalerate increasing rapidly and the increase in time coincided with the onset of fruit aroma .the changes of pectin content reduced the hardness of the fruit . Yellowing bananas occurs due to the loss of chlorophyl without or just little formation of pure carotenoid subtance. The changes of peels colour The first colour changes that happened is the loss of green colour. so the fruit will be soft eventually. The hydrolytic chlorophylase action could breakdown chlorophyl into part of phytol chlorophyl and porphyrin core . and isovalerate either in the form of free or bound. Apparently the green colour turns into yellow as time goes by. The changes of fatty acids during ripening process has been investigated by Ueda et al in 1970. The changes of Aroma Ripening process usually increase the amount of simple sugars that gives a sweet taste (due to starch is converted into simple sugar). Especially. These trends are also found in bananas ( Von Loeseoke .when chlorophyl is under acidic conditions may also form Mg+ ion that existed at the center of porfirine functional group and turned into feofitin . reported that the chlorophylase enzyme is Some scientist responsible for the decomposition of the chlorophyl. 1950) . then the peels colour changes gradually. b. propyonate .decreased . 3. Further information about this condition would be explain on the next part. decreased organic acids and phenolic compounds that reduce sour taste . and the increase of atsiri substances gives a distincitve flavor to banana . The results showed that the fruit contains acetic acid. isobutyrate . Physical Appearance of Banana during Ripening Bananas may be divided into seven different degrees of ripeness in accordance with their external color: 1 2 3 5 6 7 4 Figure 1.slideshare. Banana ripening Process Source :http://www.1 1.net/pxkohli/ripening-procedure?qid=91bf066f-eaa2-4db09adc-9337654cdc19&v=&b=&from_search=4 Degree of Appereance of Peel Ripeness 1 Green 2 Characteristiccs Color at time of loading (freshly picked) Green with faint hint Color at time of unloading amd when the maturing of yellow process has begun.1. however there is still some time before they are ready to eat . The fruit is sweet. Correct degree of ripeness for ordering by wholesalers and retailers and delivery from ripening warehouse 5 Yellow with green tip All yellow with green tip on crown. If it stays yellow. a drop of iodine on a slightly rotten part (not skin) of a banana will turn a dark-blue or black color. Its aroma and flavor are at their best.3 More green than The ripening has begun in earnest and the fruit is yellow now increasing its natural sugar content. 4 More yellow than That familiar creamy texture is developing now. the skin is very sensitive to mechanical influences. and green as the natural sugar content rises the fruit is getting ready for eating. When the fruit is this ripe. creamy and on the firmer side. as the fruit can still be kept for several days 6 Completely yellow Fruit appears at its best and is very tasty.Iodine can be used to determine whether the fruit is ripening or rotting by showing whether starch in the fruit has turned into sugar. Best condition for retail sale. the flesh is perfect and has softened for easy mashing and blending Ripening indicator that commonly used is Iodine. The sugar content is now at its peak. then most of the starch had converted to sugar . the flesh is changing from the chalky hardness of under ripe fruit. For example. Even though it is delicious it still does not have its complete full sweet flavor. The fruit also starting to soften as it ages heading towards its top sugar content 7 Yellow with brown spots Small brown spots indicate that the fruit is fully ripe. since starch is present. 2. Carbohydrate content of banana pulp at different stages of ripeness Source : http://www. Glucose and fructose are major sugars in banana pulp. Sucrose.5 to 0. It is the primary substrate in enzymatic browning.slideshare. increases to 15-20% in ripe pulp.Insoluble protopectin decreases from 0. decreasing to about 1% in the ripe fruit. maintaining a constant proportion of 66% sucrose. Tablel 1. the starch is hydrolysed. Cellulose decreases slightly during ripening.net/MinPiyusha/13-fet1012-banana (ii) Phenolic Compounds Dopamine was reported to occur in high concentration (700 µg/g fresh weight) in bananas peel and to be present in pulp (8 µg/g fresh weight). Sugar normally 1-2% in the pulp of green fruits.3% and soluble pectin a corresponding increase during ripening. During ripening.1. The hemicellulose makes up 8-10% of fresh banana pulp in green fruit. Chemical Changes in Banana during Ripening (i) Carbohydrate Sugar is a major carbohydrate in mature unripe banana. only 1-2% remaining in a fully ripe fruit. 14% fructose and 20% glucose. It is further confirmed that Dopamine is the only major phenolic constituent in banana peel.Loss of astringency during ripening of banana results from increased polymerization of the tannins. These sugars increases during ripening. . A rise in the activities of all the enzymes.The green banana peel contains about 50-100 µg/g fresh weight of chlorophyll.5 µg/g fresh weight of carotene. A banana like flavour was assigned to the amyl and isoamyl esters of acetic. propionates and butyrates together with n-hexane.(iii) Flavor Constituents Several volatile compounds have been isolated and identified in banana.The enzymatic decarboxylation of oxalate may account for the disappearance of astringent taste during ripening. chlorophyll is lost and total yellow pigment remains approximately constant. peroxidase and catalase increased considerably in three cultivars of banana fruits stored for 5 weeks at 20 0 C. acid phosphatase. Ripe banana aroma was due to a mixture of some 20 saturated acetates. During ripening. whereas the oxalic acid is metabolized and decreased.2-19. (iv) Organic Acids Malic acid has been identified as the main acid in banana with substantial quantities of oxalic and citric acid in the pulp. having a maximum about 1. propionic and butyric acids whereas alcohols and carbonyls gave odours described as green. (v) Pigments The change in colour of fruit from green to yellow is the most obvious change during ripening. was observed during ripening at 200C. 5-7 µg/g fresh weight of xanthophyll and 1.1 times their initial level. . woody or musty. Chlorophyllase activity in banana peels increases sharply at the onset of the climacteric rises to a peak which coincides with the climacteric peak and then falls to near zero in the post climacteric period. (vi) Enzymes Banana fruits contain several hydrolytic and oxidative enzymes. starch phosphorylase.5-3. The relative activities of alpha-amylase. The malic acid increases substantially upon ripening. having higher rates of respiration tend to have shorter storage life than those with lower rates of respiration.Once the respiration ends. senescence of the banana fruit starts thereby contaminating it with microorganisms and decaying of the fruit. ripening starts.3. Ethylene shortens the preclimacteric period. During ripening.1. Once ripening starts. ethylene causes rapid initiation of the climacteric respiratory response and accelerates ripening. Graph1.1.net/MinPiyusha/13- (ii) Ethylene Production Ethylene (C2H4) is a gaseous plant hormone which determines the time between harvest and senescence. Biologocal Factors (i) Respiration The process of respiration involves combining O2 in the air with organic molecules in the tissue to form CO2 and Water.3. bananas ripen within 1-2 days. Bananas.0 ml/l. Factors Involved during Ripening process 1. for 1 day. When ethylene is applied to bananas.slideshare. at a concentration as low as 0. banana produces larger amounts of ethylene than nonclimacteric fruits. . at high concentrations.1-1. Banana has moderate rate of respiration of around 10-20 mg CO2 kg^-1 h^-1 at 5°C. Respiration rate activity Source : http://www. Water loss causes plantain to lose its firmness. fruit loses little or no moisture. do not store unripe fruits with ripe fruits. The rate of water loss depends on the ambient RH. a sealed container. respiration rate falls when ethylene is removed. Also. ripening period reduced by 9 days or 50%. at a high rate of weight loss. and ripening period is . loss of water means economic loss. the peel becomes soft and shriveled. Therefore. water loss reduces visual quality. only a 1 day or 5% reduction in the ripening period occurred. a small increase in weight loss has a critical effect on ripening. Therefore. This is the best time for handling. and increase the ripening period. Additionally. relative to the maximum amount of water vapor that can be held in the air. (iii) Transpiration and Relative humidity Where banana fruit is sold on a weight basis. for the same 2% change from 8% to 10% per day. A rise in respiration rate may occur more than once in nonclimacteric fruits. that is.When nonclimacteric fruits are exposed to ethylene. RH is the amount of water vapor present in the air. for example. at a given temperature. fruits are less susceptible to physical damage and pathological attack. saturated air being 100% RH. the water content of the air within the container increases or decreases until it is in equilibrium with the fruit. store plantain in thatched or ventilated areas to prevent the build up of ethylene.The water equilibrium principle applies when fruit is stored.For example. During the preclimacteric period. fruits show an increased rate of respiration. for bananas. and marketing. At an ambient RH of 95-100%. When banana is placed in an enclosed space. plastic sheets placed over stacks of fruit for shade increase the level of ethylene within the plantain stack and increase the rate of ripening. the climacteric is autocatalytic. stimulate the climacteric response. However. the process cannot be stopped until the fruit is ripe. Poor storage methods allow a build up of ethylene. However. transportation. once started. However. and ripening period reduces. The rate of water loss depends on the ambient relative humidity (RH). For a 2% change from 2% to 4% weight loss per day. as humidity decreases. depending on cultivar. Impact bruising: Dropping of bananas may induce browning of the flesh without damage to the skin. becomes evident as the bananas ripen. failure to ripen. moderate chilling injury will result from exposing maturegreen bananas to one hour at 10°C (50°F). Chilling injury results from exposing bananas to temperatures below 13°C (56°F) for a few hours to a few days. and Fusarium roseum--which attack the cut surface of the hands. maturity. Skin abrasions: Abrasions result from skin scuffing against other fruits or surfaces of handling equipment or shipping boxes. Colletotrichum musae.8°C (55°F). or 72 hours at 12. From the rotting hand tissue the fungi grow into the finger neck and with time.2°C (54°F). dull or smokey color. down into the fruit.unaffected. Deightoniella torulosa. and ripening period reduces. (v)Pathological Disorders Crown rot: This disease is caused by one or more of the following fungi: Thielaviopsis paradoxa. especially in wounds and skin splits. However. in severe cases. (iv) Physiological and Physical Disorders Chilling injury: Symptoms include surface discoloration. and. Anthracnose: Caused by Colletrichum musae. For example. water loss from scuffed areas is accelerated and their color turns brown to black. 5 hours at 11. . When exposed to low (<90%) relative humidity conditions. 24 hours at 12.7°C (53°F). Lasiodiplodia theobromae. and temperature. flesh browning. the rate of water loss increases. subepidermal tissues reveal dark-brown streaks. Chilled fruits are more sensitive to mechanical injury. More the water loss. . Environmental Factors (i) Temperature Physiological studies on bananas show that storage life decreases as external temperature increases over the range 15-35ºC. Cigar-end rot: Caused by Verticillium theobromae and/or Trachysphaera fructigena. This temperature will maintain fully mature. Fruit respiration depends on many enzymatic reactions. It’s effect on harvested fruit desirable (degreening & ripening) or undesirable (abbreviated storage. 1. lesser is the ripening period.2. it causes rapid initiation of the climacteric respiratory response and accelerates ripening. at temperatures below 11ºC. Consequently. optimum storage temperature for plantain and banana fruits is 13-14ºC. (iii) Relative Humidity RH governs the water losses occurring in the fruit. More CO2. and the rate of these reactions increases exponentially with increase in temperature. The relationship between ripening period and temperature is due to fruit respiration. The invaded flesh becomes soft and watersoaked. Storage period can extend to 4 weeks when plantain and banana are harvested up to 4 weeks before full maturity. The rotted portion of the banana finger is dry and tends to adhere to fruits (appears similar to the ash of a cigar). This explains why ripe fruits deteriorate quickly. lesser O2 is not good and very high concentrations of O2 ripens the banana rapidly. (ii) Air Composition The atmospheric gases present can be desirable and undesirable. fruits suffer chilling injury. A 1ºC reduction increases storage period by 1-2 days. ripe fruits lose sugar resources at a higher rate than unripe fruits. (iv) Ethylene At high concentration of Ethylene. softening). Therefore. ripe and unripe fruits for 1-2 weeks. Studies show that ripe fruits respire at approximately 4 times the rate of unripe fruits. Stem-end rot: Caused by Lasiodiplodia theobromae and/or Thielaviopsis paradoxa. which enter through the cut stem or hand.3.However. Hang the bananas on a banana tree. or vinegar. . Eat or refrigerate the bananas as spots develop on the skin and before they are overripe.Common Home-scale Methods for Storing Banana Select green firm fruit without dark spots or abrasions on the peel. If bananas are already pretty ripe. Add an apple or a tomato to the bag to ripen the bananas in less than 1 day. Keep ripe bananas at room temperature if it is to be consumed within a few days. Banana Storage 2. Keep sliced bananas fresh. pineapple juice. Avoid bananas that have a gray tint and look dull in color. which hold too much moisture and could cause the fruit to rot. 2.2. Another way to speed up the ripening process is to place the bananas near other ripe fruit in a bowl. Store green bananas at room temperature.2. Never store bananas in plastic bags. Cover the slices in a bit of lemon juice.How to Storing Ripe Banana ? Pull the bananas apart from the bunch. This will keep each banana fresher for longer. Banana trees and hangers allow air to circulate and avoid"resting bruises" on the fruit.1. Leave yellow-green ripening bananas exposed to air at room temperature for a few days. then keep them fresh and yellow for longer by pulling each banana away from the bunch. such as other ripe bananas.all of which will keep it fresher for longer. Put green bananas into a brown paper bag to speed up the ripening process. Place some tape over the plastic wrap for some extra security. The peel willcontinue to turn brown. but the fruit will stay fresh and firm for 1 to 2 weeks.google. Alternately. from reaching other parts of the fruit and making it ripen too fast. which is produced naturally during the ripening process. while ripening faster itself. but does not stop it. and it will slow down the ripening process of the bananas. Store the ripe bananas with unripe fruit. Figure 2.slideshare. Banana stem wrap with plasticog Source : https://www.co. Refrigeration slows the ripening process considerably. separate the bananas from the bunch and then wrap the step of each one individually. . This will prevent ethylene gas.ssl&ei=r0bHVuarOIagugSv26aoBg Put the bananas in the produce drawer of your refrigerator after they are fully ripe. Rewrap it carefully every time after removing a banana from the bunch.id/?gws_rd=cr.net/MinPiyusha/13- Wrap the stems of the bananas in plastic wrap. Figure 3. Take an unripe pear or avocado and place it near the bananas.. Combination of fresh fruits Source : http://www. Portion the banana into the amounts you need to make a recipe. it only able to store single banana and also disable to keep banana fresh longer. But this type of container is just able to protect banana from physical contact.Banana Container (i) Banana Bunker The Banana Bunker is a flexible.ssl&ei=r0bHVuarOIagugSvdd26aoBg Store bananas in the freezer for several months.such as : Figure 4. Put portioned bananas into zipper freezer bags or plastic containers and store them in the freezer.3. These allow you to adjust the bunker to fit nearly any size and shape of banana. Appreance of rippen banana Source : https://www.storing ripe bananas in the refrigerator will preserve their delicious taste for longer. plastic device specifically designed to protect bananas from a messy. . Peel bananas and cut them into chunks ormash them before freezing.google. squishy fate. eventhough their peels may turn black.It also had design features open ends and a flexible and detachable midsection.Accordingly. 2.co.id/?gws_rd=cr. But this type of container is just able to protect banana from physical contact. this device fits over 90% of commercially available bananas. Figure 6.Figure 5. Because.com/ DAFTPUS http://www.com/ .highly curved bananas can be straightened slightly to fit into upper curve and very straight bananas can be bent ever so slightly to fit into the mold. it’s only able to store single banana and also disable to keep banana fresh longer. Banana guard Source : http://bananaguard. Banana bunker Source : http://bananabunker.bananaguard.com/ (ii) Banana Guard The Banana Guard is quite same as the banana bunker but it doesn’t had a flexibe feature. According to their website. html .spoonuniversity.au/bananas/harvesting-packing-and-storing-bananas-oria http://www.slideshare.net/pxkohli/ripening-procedure?qid=91bf066f-eaa2-4db0-9adc9337654cdc19&v=&b=&from_search=4 https://www.com/ https://pitt.scienceabc.http://bananabunker.com/how-to/5-genius-ways-to-quickly-ripen-bananas/ http://www.net/AnushaBabooa/banana-ripening?next_slideshow=1 https://www.slideshare.agric.com/nature/bananas-change-colour-upon-ripening.slideshare.net/ebanreb07/how-to-keep-bananas-fresh?qid=504adb14-fd304c94-8ad1-52cda5c373a5&v=&b=&from_search=47 http://www.gov.wa.