Yield,characteristics and composition of banana juice extracted by the enzymatic and mechanical methods

A comparative study of the enzymatic and mechanical banana juice extraction methods and the respective juices produced was carried out using Kayinja bananas (ABB genotype) imported from Uganda. In the enzymatic extraction process, macerated ripe banana pulp was incubated with a commercial enzyme preparation (Pectinex Ultra SP‐L) at 50 °C for 2 h. In the mechanical extraction process the ripe banana pulp was mixed with stretched strips of polythene and worked with a dough mixer at room temperature for 20 min (on average) until the juice appeared. Significantly (p < 0.05) higher ‘pure’ juice yield (604 g kg^?1 pulp) was obtained with the enzymatic method than with the mechanical method (541 g kg^?1 pulp). However, adding water to the spent pulp from the mechanical process and extracting dilute juice improved the juice yield to 757 g kg^?1 pulp. The enzyme‐extracted juice had significantly (p < 0.05) higher soluble solids, titratable acidity, fructose, glucose, total nitrogen, density and mineral potassium. However, the mechanically extracted juice had significantly higher sucrose, pH and viscosity. Although the mechanical extraction process suffers from occasional juice extraction failures, it offers an opportunity to extract banana juice without excessive energy expenditure, and the juice produced is wholesome with a superior flavour to that produced by the enzymatic method. © 2002 Society of Chemical Industry     

Evaluation of the Antioxidant Properties of the Brazilian Cerrado Fruit Annona crassiflora (Araticum)

Annona crassiflora, known commonly as araticum, is an exotic tropical fruit consumed mainly by native people of the Brazilian Cerrado (2nd biggest biome of Brazil). In this study, pulp, seed, and peel of slight ripe and overripe fruits were extracted using ethanol and water. The extracts showed high content of total phenols and were screening for their potential as antioxidants using the in vitro model 1,1‐ dipheniyl‐2‐picryl hydrazyl (DPPH). The ethanol extracts of peel and seeds showed IC50 of 48.82 μg/mL and 31.14 μg/mL, respectively, for the slightly ripe fruits. As the ethanolic fractions of araticum showed the highest antioxidant activity, they were selected for testing of its effect on lipid peroxidation. The ethanolic extracts of slightly ripe fruits showed IC₅₀ of 4.44 μg/mL, 1.72 μg/mL, and 8.62 μg/mL for the peel, seed, and pulp, respectively. This is the 1st report on the antioxidant properties of the extracts of araticum. Owing to these properties, the studies can be further extending to exploit them for their possible application as natural antioxidant for cosmetic, supplements, and functional ingredients for food products.     

Determination of optimum harvest maturity and physico-chemical quality of Rastali banana (Musa AAB Rastali) during fruit ripening

BACKGROUND: A series of physico‐chemical quality (peel and pulp colours, pulp firmness, fruit pH, sugars and acids content, respiration rate and ethylene production) were conducted to study the optimum harvest periods (either week 11 or week 12 after emergence of the first hand) of Rastali banana (Musa AAB Rastali) based on the fruit quality during ripening. RESULT: Rastali banana fruit exhibited a climacteric rise with the peaks of both CO₂ and ethylene production occurring simultaneously at day 3 after ripening was initiated and declined at day 5 when fruits entered the senescence stage. De‐greening was observed in both of the harvesting weeks with peel turned from green to yellow, tissue softening, and fruits became more acidic and sweeter as ripening progressed. Sucrose, fructose and glucose were the main sugars found while malic, citric and succinic acids were the main organic acids found in the fruit. CONCLUSION: Rastali banana harvested at weeks 11 and 12 can be considered as commercial harvest period when the fruits have developed good organoleptic and quality attributes during ripening. However, Rastali banana fruit at more mature stage of harvest maturity taste slightly sweeter and softer with higher ethylene production which also means the fruits may undergo senescence faster than fruit harvested at week 11. Copyright © 2011 Society of Chemical Industry     

Rheological and functional properties of flours from banana pulp and peel

Unripe banana flour can be an alternative to minimize post‐harvest loss and to increase the aggregate value of banana fruit. Flour from unripe banana is rich in phytosterols and resistant starch, being proposed as health food. Flours from unripe banana peel and pulp were evaluated on their composition, phytosterols content, thermal and rheological properties, and pasting profiles. High amounts of β‐sitosterol, campesterol, and stigmasterol were found in flour from banana peel. These samples showed lower viscosity values of pasting profiles, lower energy enthalpy on gelatinization, and higher temperature of gelatinization than those ones from pulp. Anti‐oxidant treatment of fruits with citric acid does not change pasting profiles of flours from pulp, but resulted in slight increase in viscosity, suggesting that structure of starch could be modified by acidification.     

Comparing physicochemical properties of banana pulp and peel flours prepared from green and ripe fruits

Banana pulp and peel flour prepared from green and ripe Cavendish banana were assessed for physicochemical properties such as pH, total soluble solids (TSS), water holding capacity (WHC) and oil holding capacity (OHC) at 40, 60 and 80 °C, colour values L^∗, a^∗ and b^∗, back extrusion force (BEF) and viscosity. Data obtained were analysed by MANOVA, discriminant analysis and cluster analysis. All statistical analyses showed that physicochemical properties of flour prepared from pulp and peel, and green and ripe banana were different from each other. TSS, WHC40, WHC60 and BEF can be used to discriminate between peel and pulp flour, whilst TSS and viscosity can be used to discriminate between flour prepared from green and ripe banana.     

玉米芯高温热解提取戊聚糖工艺优化

以玉米芯为原料,采用高温热解法提取戊聚糖,在单因素试验基础上,采用正交试验法对提取工艺参数进行优化,利用高效液相色谱法对戊聚糖提取液进行组分分析。结果表明:最佳提取工艺条件为固液比1∶15(g/mL),热解温度180℃,热解时间60 min,在此条件下提取率为25.84%。色谱图结果显示:提取液中含有大量的戊聚糖、木二糖、木三糖、木四糖、木五糖和木六糖,为后续酶解工艺制备低聚木糖提供原料。     

Variation in 1‐fructo‐exohydrolase (1‐FEH) and 1‐kestose‐hydrolysing (1‐KH) activities and fructo‐oligosaccharide (FOS) status in onion bulbs. Influence of temperature and storage time

Effects of storage temperature and duration on 1‐fructo‐exohydrolase (1‐FEH) and 1‐kestose‐hydrolysing (1‐KH) activities and trisaccharide (Tri) and fructo‐oligosaccharide (FOS) status in onion bulbs var Tenshin kept for 24 weeks at 10 and 20 °C were investigated. 1‐FEH activity peaked sharply after 10 weeks and seemed to be triggered by a decrease in sucrose content. 1‐KH activity increased during the first 8 weeks and remained stable during the last 8 weeks. Contents of Tri, FOS and total FOS decreased abruptly during the first 8 weeks; however, at 10 °C, contents of Tri, FOS (DP 3–12) and total FOS were lower than those at 20 °C. The consumption rate of fructo‐oligosaccharides also appeared to be higher at 20 °C than at 10 °C, despite the slight degradation in activities observed at this low temperature. 1‐FEH seems to be under the control of a triggering signal which induces its activity, and sucrose seems to be this biochemical signal which initiates dormancy release and the onset of sprouting, as found previously. Thus changes in carbohydrates seem to be a strong indicator of the end of the dormant state of the bulb and the beginning of the sprouting period. Copyright © 2004 Society of Chemical Industry     

甘蔗渣酶法制备低聚木糖的研究

对甘蔗渣酶法制备低聚木糖进行了研究,得到酶法制备低聚木糖的优化酶解条件为:在50℃的静止恒温水浴中pH为5.4的最适反应条件下,底物浓度为1.47%,加酶量为1000IU/g底物,酶解时间为60min,低聚木糖的得率占可溶性总糖的30%(二糖到七糖的和)。利用活性炭柱层析分离低聚木糖的洗脱条件为:用10%的乙醇水溶液可以洗脱单糖;15%的乙醇水溶液可以洗脱二糖;20%的乙醇水溶液可以洗脱二糖和三糖;25%的乙醇水溶液可以洗脱三糖、四糖和五糖;30%的乙醇水溶液可以洗脱三糖到七糖的混合糖。     

The content of chlorogenic acids in tropical fruits

This work investigates the content of feruloylquinic (FQA), caffeoylquinic (CQA) and dicaffeoylquinic (diCQA) acids in the peel, pulp and seed of 22 tropical fruits from Brazil. 3‐CQA, 4,5‐diCQA and 4‐ and 5‐FQA were not detected in any of the fruits analysed. Relatively small amounts of 4‐CQA (4.0–48.7 mg kg^?1) were found in the peel and/or pulp of seven of the fruits; only the peel of Artocarpus heterophyllus was significantly (p < 0.05) richer in this acid (1000 mg kg^?1). The distribution of 3,4‐ and 3,5‐diCQA in different parts of the fruits was relatively poor, only reaching levels of up to 16.4 mg kg^?1. The peel of A heterophyllus also showed the highest amount of 5‐CQA (13 000 mg kg^?1), while the seed of most fruits generally contained a lower amount of this acid than the peel or pulp. On the basis of the 5‐CQA content found in the pulp, 15 of the fruits were classified as follows: very low concentration (4.4–15.8 mg kg^?1), low concentration (28.9–66.4 mg kg^?1), medium concentration (132 mg kg^?1), high concentration (473–474 mg kg^?1) or very high concentration (1730 mg kg^?1); however, no 5‐CQA was detected in the pulp of the other seven fruits. Thus 5‐CQA was the major chlorogenic acid present in most of the tropical fruits studied and was generally accompanied by small amounts of 4‐CQA and 3,4‐ and 3,5‐diCQA. © 2002 Society of Chemical Industry     

Analysis of phenolic compounds including tannins,gallotannins and flavanols of Uapaca kirkiana fruit

Tannins and phenolic acids were extracted from Uapaca kirkiana unripe pulp, seed coat, peel and embryo, as well as from ripe pulp, seed coat, embryo and peel portions of the fruit. Extraction was done using 50% methanol. More tannins were detected in the embryos of both ripe and raw fruit. Both ripe and raw seed coat contained the least amounts of tannins. The flavanoids and gallotannins also followed the same trend, with most of them in the embryos of both, the ripe and raw, fruit portions whilst the least were found in the seed coat. Tannins were, however lost during sun-drying compared to oven-drying, even though the differences were not very large. Also, raw fruits showed high concentrations of tannins compared to the ripe fruits. Hydroxybenzoic acid was found in the peel and pulp but none was detected in the seed coat or in the embryo. Similar phenolic acids were detected in the seed coat, except for caffeic acid and protocatechuic acid, detected in the embryo by both the UV florescence and Folin spray.     

Alginate Immobilization of Banana Pulp Enzymes for Starch Hydrolysis and Sucrose Interconversion

A model system has been established that utilizes the entrapment of whole banana pulp homogenates within a calcium alginate matrix in the form of bead that is effective in assaying for enzyme activity in the pulp of the ripe banana fruit. This medium retained enzyme activity for amylase, maltase and invertase and provided indirect evidence of sucrose synthetase activity. A cyclic pathway has been proposed for the biosynthesis and hydrolysis of sucrose in the pulp of ripening banana fruit.     

Lipid in Ripening Banana Fruit

SUMMARY: Lipid extracts were isolated from unripe and ripe banana pulp and peel and the fatty acid composition of the extracts was determined. Unsaturated acids, particularly linoleic and palmitoleic, decreased about 3-fold in the pulp while more than a 2-fold increase in stearic acid occurred. In general, unsaturated fatty acids decreased in both the pulp and peel during ripening. The peel contained almost 4 times more lipid than the pulp.     

基于成熟度研究不同品种香蕉多酚含量及抗氧化活性的差异

为评价新品种GC30加工蕉的抗氧化功效,开发其相关产品,拓宽香蕉产业链,本文以GC30加工蕉和4个主栽品种GC02天宝高蕉、GC07鸡蕉、GC09粉蕉、GC25大蕉为对象,研究不同成熟度（1级和7级,1级全果呈暗绿色,7级全果呈黄色）下香蕉皮、肉及果的多酚含量和抗氧化活性,并基于主成分分析法,对不同品种及成熟度香蕉抗氧化活性进行综合评价。结果表明,所有品种的香蕉皮多酚含量均最高（P<0.01）,7级香蕉皮、肉的多酚含量与其1级的没有显著性差异（P>0.05）,不同品种的香蕉皮多酚含量具有显著性差异（P<0.05）,其中7级GC30香蕉皮的多酚含量最高;不同品种的香蕉果、肉、皮的DPPH自由基清除率、超氧阴离子自由基清除能力和抑制羟自由基能力没有显著性差异（P>0.05）,所有品种的7级香蕉皮、肉、果的DPPH自由基清除率、超氧阴离子自由基清除能力和抑制羟自由基能力极显著高于其1级香蕉皮、肉、果（P<0.01）;所有品种的香蕉皮金属螯合率极显著大于香蕉果、肉（P<0.01）,而品种和成熟度对香蕉皮、肉、果的金属螯合率没有显著影响（P>0.05）;不同品种熟香蕉果、肉、皮的抗氧化活性优于生香蕉果、肉、皮的抗氧化活性,其中7级GC30香蕉皮抗氧化活性综合评价排名最高。通过对不同品种和成熟度香蕉的功效成分及抗氧化能力的研究,为香蕉品种的选育、分级分类加工与应用提供理论依据,对增加香蕉产业的收益具有重要意义。     

β-D呋喃果糖苷酶合成低聚果糖的工艺研究

以蔗糖为底物 ,采用来源于米曲霉中的 β -D -呋喃果糖苷酶 (EC3 2 1 2 6)合成低聚果糖 ,酶反应最佳条件为 :反应温度 35℃ ,酶反应体系的pH为 8 0～ 8 2 ,酶浓度 2 7IU/ g(蔗糖 ) ,酶反应时间为 8h。低聚果糖的最大转化率为 5 4% ,82 %的蔗糖被转化     

Sugar Composition and lnvertase Activity in Prickly Pear Fruit

Sucrose was the predominant sugar in peel samples and present in lesser amounts in pulp and juice samples of prickly pear fruit. The relative total content of glucose and fructose differed among species and within fruit tissues. Acid invertase activity was found in all fruits examined while neutral invertase activity was found in two of the three species. Red-skinned fruits had no neutral invertase activity and yellow-skinned fruits had relatively high neutral invertase activity. When both invertase activities were added, a pattern of distribution of invertase activity that corresponded with sucrose levels within fruits was observed. The overall total invertase activity levels in red-skinned fruits were about twofold that of the yellow-skinned fruits and fourfold that of purple-skinned fruits.     

Carbohydrate and protein composition of banana pulp and peel as influenced by ripening and mold contamination

The effects of firewood-obtained ash and a fruit mold, Botryodiplodia theobromae, on the total proteins and some carbohydrate constituents of the banana fruit were investigated. A slight decrease in moisture content of the ash-ripened peel was recorded. Fruit infested with the mold showed a complete loss of glucose and fructose and a drastic reduction in total sugars. Cellulose was found to remain fairly constant during ripening while the starch content fell as ripening progressed. Low levels of proteins were recorded both in the peel and pulp of fruit.     

不同品种和产地梨果实可溶性糖组分比较

目的 了解不同品种和不同产地梨果实可溶性糖含量的差异。方法 采用高效液相色谱(high performance liquid chromatography, HPLC)分析法, 对河北省赵县6个梨品种果皮、果肉和果心, 河北省赵县、晋州、辛集6个梨品种果肉, 以及山东、河北、河南、北京、山西5个省份的‘黄冠’梨果肉中可溶性糖组分(蔗糖、葡萄糖、果糖、山梨醇)进行了分析。结果 每个品种的果皮、果肉、果心的糖组分含量、不同产区梨品种果肉糖组分含量、5省‘黄冠’梨果肉总糖含量几乎都存在显著性差异; 果皮中除‘圆黄’外, 剩余5品种皆是蔗糖含量最低。结论 不同品种、不同部位、不同产地的梨果实糖积累有差异, 值得深入研究。     

贮藏温度对香蕉糖酸组分的影响

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Ripening-associated changes in the amounts of starch and non-starch polysaccharides and their contributions to fruit softening in three banana cultivars

BACKGROUND: Fruit softening is generally attributed to cell wall degradation in the majority of fruits. However, unripe bananas contain a large amount of starch, and different banana cultivars vary in the amount of starch remaining in ripe fruits. Since studies on changes in pulp firmness carried out with bananas are usually inconclusive, the cell wall carbohydrates and the levels of starch and soluble cell wall monosaccharides from the pulps of three banana cultivars were analysed at different ripening stages. RESULTS: Softening of Nanicão and Mysore bananas seemed to be more closely related to starch levels than to cell wall changes. For the plantain Terra, cell wall polysaccharide solubilisation and starch degradation appeared to be the main contributors. CONCLUSION: Banana softening is a consequence of starch degradation and the accumulation of soluble sugars in a cultivar‐dependent manner. However, contributions from cell wall‐related changes cannot be disregarded. Copyright © 2011 Society of Chemical Industry     

Comparison of the physico‐chemical characteristics of a new triploid banana hybrid,FLHORBAN 920, and the Cavendish variety

BACKGROUND: The physico‐chemical characteristics of a new banana triploid hybrid (FLHORBAN 920 cultivar, AAA group), partially resistant to Yellow Sigatoka and Black Leaf Streak diseases, were measured throughout ripening and compared with those of the Cavendish banana. RESULTS: The greatest differences between FLHORBAN 920 (F920) and the Cavendish variety were observed at intermediate maturity, when bananas were yellow with green tips or yellow. The F920 bananas have more dry matter and starch than those of Cavendish. The total polyphenol contents of F920 bananas were three‐fold higher than Cavendish. The sucrose contents were 1.5‐fold higher in F920 fruits, whereas glucose and fructose contents were two‐fold higher in Cavendish fruits. The F920 fruits had fewer esters, carbonyls and phenolic ethers than Cavendish. The two varieties differed in the composition in methyl‐branched (alcohols and esters) and phenolic ether volatile compounds. CONCLUSION: These characteristics, coupled with resistance to the principal banana diseases, suggest that the F920 variety should be developed further. Copyright © 2008 Society of Chemical Industry