Characterization of Starch and Fiber of Banana Fruit

Mature green and ripe bananas were analyzed for moisture, protein, starch, sugars, ash, and fiber. Ripe banana fruit contained 1.27% dietary fiber, as determined by the detergent method. Hemicellulose content was higher than that of most fruits and vegetables whereas cellulose and lignin contents were lower. The morphological and physicochemical properties of isolated starch were determined. Starch granules were irregularly shaped, with spheroid and elongated forms predominating. Both the Brabender amylograms and the two-stage swelling patterns of the starch were similar to those reported for mung bean starch.     

ORGANIC ACID AND SUGAR CONTENTS OF SCUPPERNONG GRAPES DURING RIPENING

Changes in the principal organic acids and sugars of Scuppernong grapes ( V. rotundifolia ) were followed during the ripening season. The vines were sampled bi-weekly during the initial stages of berry development and then weekly as harvest approached until the "overripe" stage was reached. At the ripe stage, malate and tartrate constituted approximately 90% of organic acids with trace quantities of pyruvic, fumaric, succinic, citric and quinic acids. Glucose, fructose and sucrose constituted approximately 90% of the sugars with trace quantities of galactose and maltose. Malate concentration increased during the early stages of ripening, peaked and decreased to a plateau at the ripe stage. Tartrate decreased steadily until it leveled at the ripe stage. Sugars began to accumulate at veraison, increased rapidly thereafter, and leveled at the ripe stage. At harvest, Scuppernong grapes contained 1.60% total acid and 9.45% total sugars on a whole berry basis. Individual constituents were 0.67% malate, 0.92% tartrate, 3.86% fructose, 3.98% glucose, and 1.61% sucrose.     

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     

Metabolites in golden delicious apples as possible parameters of acceptability

The ripening process of “Golden Delicious” apples, harvest 1972, during storage at 4 °C under controlled atmosphere, was assessed sensorially with a palatability test based on the attributes flavour, sweetness or sourness, and texture. After 130 days of storage 50% of the apples had flavour pertaining to ripe (pleasant to eat) stage and 50% pertaining to overripe (unpleasant to eat). The same proportions for sweet-sour relation (ripe and overripe) and texture (ripe and overripe) were reached after 180 days of storage, when fruits became clearly inedible. This showed that flavour was the first attribute to deteriorate and therefore it constituted the limiting factor of the internal quality of apples. Consequently the following criterion was adopted: the internal quality of a batch of apples remained satisfactory until the proportion of apples assessed as of ripe flavour (40–50 %) was similar to the proportion of apples with overripe flavour (40–50%). This moment coincided with the inflexion point in the graph of sucrose content per initial fresh weight of apples against time and with the fall of L-malate below about 0.40%. The inflexion point of the graph for citrate was earlier than the inflexion for sucrose.     

EVALUATION OF ARTIFICIAL NEURAL NETWORKS FOR PINEAPPLE GRADING

The objective of this study is to evaluate resonant frequency, firmness and soluble solids for pineapple classification using artificial neural networks (ANNs) as the analytical tool. A sample of 149 pineapples was classified based on their internal qualities into five classes: unripe, partially ripe, ripe, partially overripe and completely overripe. The developed ANN model successfully classified pineapples into merely three classes as unripe, ripe and completely overripe. The most effective model was obtained when both resonant frequency and soluble solids were included in the model. The classification accuracy was more than 83% for all three classes.     

INFLUENCE OF PLANTAIN AND COOKING BANANA CULTIVAR AND RIPENESS ON PROCESSED PRODUCT QUALITY

The plantain cultivars (Musa spp., AAB group), Agbagba, Obino L'Ewai and Ubok Iba, and two cooking bananas (ABB group), Bluggoe and Fougamou, were processed into a paste (fufu), fried chips and fried ripe fruit (dodo) at six different ripening stages based on peel color. Boiled peeled cooking bananas and Agbagba produced smoother pastes. Paste ratings in the boiled peeled fruits increased as plantain ripened but not cooking bananas. Amounts of oil absorbed by Bluggoe fried chips were lower than those absorbed by Fougamou and plantain chips. Quantity of oil absorbed by the chips increased at ripeness rating 2, then declined as the fruit ripened further. In the case of dodo, Bluggoe absorbed the greatest amount of oil. The quantity of oil absorbed by dodo increased with ripeness rating in the cooking bananas but not in plantains.     

品种、部位和成熟度对烟叶淀粉含量及评吸质量的影响

用红大和K326烤烟品种的上、中、下3个部位的未熟烟叶、初熟烟叶、适熟烟叶和过熟烟叶进行烘烤对比试验,测定烤前、烤后烟叶淀粉含量,并对初烤烟叶进行评吸鉴定。结果表明,2个品种烟叶的淀粉含量差异达到显著或极显著水平,烟叶在烘烤过程中淀粉含量显著降低,不同部位鲜烟叶淀粉含量存在着极显著差异;烘烤后,中、上部烟叶与下部烟叶之间的淀粉含量差异达到极显著水平,中部与上部烟叶之间淀粉含量差异不显著;不同成熟度档次之间的烟叶淀粉含量的差异在烘烤前后均达到极显著水平。评吸结果表明,适熟和初熟烟叶香吃味较优,过熟烟叶香吃味次之,未熟烟叶的香吃味较差。讨论提出,适熟采收是降低烟叶淀粉含量,改善烟叶香吃味的一项重要技术措施。     

Changes in carbohydrate composition of seeds of Litchi chinensis sonn during maturation

The accumulation of starch and total sugar, mainly as sucrose, is a feature of seeds of the litchi cultivars ‘Deshi’ and ‘Kasba’ up to the fully ripe stage of fruits. The precocious loss of food reserves, as evidenced by a decline in starch content in over-mature seeds of senescing fruits, may be detrimental to loss of seed viability. Kinetin application leads to low contents of starch, sugar and lactic acid. This indicates that starch synthesis is possibly slowed down due to non-availability of sugars resulting from the reversal of their translocation as a consequence of kinetin application, which also facilitates aerobic metabolism of pyruvate affecting the lactate level. By contrast, cycloheximide brings about initial decline but later accumulation of starch and sugars, through a rise in sucrose content indicating an enzymic pathway and that the enzymes need to be synthesised, but the synthesis is inhibited by cycloheximide application. Similarly, enzyme-mediated lactate production is also interfered by cycloheximide application.     

Influence of Fruit Composition, Maturity and Mold Contamination on the Color and Appearance of Strawberry Wine

Color composition of strawberry wines made from ripe, overripe, and mold-contaminated fruit (Benton and Totem varieties) was monitored over 6 wk storage. Overripe fruit with its higher anthocyanin and total phenolics gave wines with better color than fully ripe fruit. Totem fruit had higher anthocyanin, lower polyphenol oxidase activity and lower total phenolics than the Benton variety and produced wines with better color. Mold contamination increased juice viscosity, reduced fermentation rate, and accelerated color degradation. Anthocyanin content and Hunter L values of wines were highly correlated with panel color evaluations.     

Oligosaccharides in Eleven Legumes and Their Air-Classified Protein and Starch Fractions

Oligosaccharide compositions of flours from dehulled seeds of eleven legumes were determined by gas-liquid chromatography and mass spectroscopy. While soybean contained 11.7% sugars, concentrations in lupine, cowpea, chickpea and lentil were about 8%; lima, navy and northern beans, field pea, mung bean and fababean contained about 5% of sugars. Sucrose represented 20–55% of the total sugars; stachyose was the principal α-galactoside in most species. In addition, high amounts of manninotriose were found in chickpea and lentil flours whereas verbascose was a major component in field pea, mung bean and fababean flours. The nine species and biotypes which contained starch were pin milled and air-classified into protein-rich and starch-rich fractions. The protein fractions were 40–90% higher than the flours in α-galactosides, especially raffinose, manninotriose, stachyose and verbascose. The starch fractions were depleted in α-galactosides, the concentrations varied from 1.2–2.8% of the fraction.     

EFFECTS OF HARVEST MATURITY ON BANANA QUALITY

Bananas (cv. Hochuchu) were harvested at 80, 90 and 100 days after inflorescence emergence for quality evaluation. At harvest, the 80-day sample had the highest flesh firmness and starch content, followed in order by the 90-day and the 100-day samples. The opposite was found for total sugars content. Titratable acidity in the 100-day fruit was significantly greater than those in the 80-day and 90-day fruits. No significant differences in flesh firmness, starch content, total sugars content and titratable acidity were noted among fruits of different maturity stages when ripe. Their eating quality was acceptable with the scores corresponding to like moderately to like very much.     

高压静电场处理对香蕉果实成熟生理的影响

以香蕉果实为试验材料,在(20±1)℃试验冷库中贮藏21d,贮藏期间用－100kV/m和－200kV/m的高压静电场连续处理并测定果实的呼吸强度、乙烯释放量、硬度、果皮颜色变化以及果肉淀粉和可溶性糖含量的变化。结果表明：连续高压静电场处理可以使香蕉果实的呼吸跃变和乙烯释放高峰提前,淀粉转化为糖的速度快而且比对照早,果皮叶绿素含量明显低于对照,同时处理后的果肉硬度下降,低于对照;并且－200kV/m处理组的效果要优于－100kV/m处理组。说明高压静电场连续处理促进了香蕉果实的成熟,尤以－200kV/m处理组比对照提前成熟4d。     

Antioxidant properties of durian fruit as influenced by ripening

The antioxidant properties of durian (Durio zibethinus Murr., cv. Mon Thong) at different stages of ripening were investigated using fluorometry, UV spectroscopy, and HPLC/DAD analyses. Total polyphenols, flavonoids, anthocyanins and flavanols in ripe durian were significantly higher (p < 0.05) than in mature and overripe fruits. Free polyphenols and flavonoids were at lower levels than hydrolyzed ones. Caffeic acid and quercetin were the dominant antioxidant substances in ripe durian. In these fruits, methanol extracts contained a relatively high capacity of 74.9 ± 7.1% inhibition using β-carotene-linoleic acid assay. Ferric-reducing/antioxidant power (FRAP) and cupric-reducing antioxidant capacity (CUPRAC) assays supported this finding. The correlation coefficients between polyphenols and antioxidant capacities of durian samples with all applied assays were about 0.98. In conclusion, the bioactivity of ripe durian was high and the total polyphenols were the main contributors to the overall antioxidant capacity.     

Biochemical changes in new plantain and cooking banana hybrids at various stages of ripening

BACKGROUND: New varieties of plantain and cooking banana with higher yields and improved pest and disease resistance are continuously being bred. There is therefore the need to study their properties during postharvest ripening. This work investigates the effects of ripening on the dry matter content, pH, titratable acidity, ascorbic acid content, browning potential, starch content and reducing and non‐reducing sugar contents of new FHIA 19 and FHIA 20 plantain and FHIA 03 cooking banana hybrids. RESULTS: The starch and ascorbic acid contents of all hybrids decreased as ripening progressed. The starch and dry matter contents of the FHIA 03 cooking banana were reduced from about 750 to < 100 g kg^?1 and from 260 to 190 g kg^?1 respectively after stage 9 of ripening, when samples had more black than yellow colour. The FHIA 03 cooking banana had the highest content of non‐reducing sugars. The titratable acidity of the FHIA 03 cooking banana was higher than that of the FHIA 19 and FHIA 20 plantains. The browning potential of all hybrids decreased after stage 7 of ripening, when samples were yellow with black spots. The FHIA 19 plantain had the lowest browning potential. CONCLUSION: Significant reductions in the dry matter, ascorbic acid and starch contents of the plantain and cooking banana hybrids were observed during the progress of ripening. The cooking banana variety contained lower levels of dry matter, ascorbic acid and starch than the plantain varieties. Copyright © 2008 Society of Chemical Industry     

Physico-chemical changes in ‘Saba’ bananas during normal and acetylene-induced ripening

Physico-chemical changes in ‘Saba’ bananas, a variety widely used as a raw material for several products in the Philippine food industry, were analysed under conditions of normal and acetylene-induced ripening.Starch degradation, the formation of reducing and non-reducing sugars and an increase in the moisture content, pectins and acidity of the pulp, occurred during ripening. Acetylene accelerated the rate of chemical change, without significantly affecting the final levels at which chemical constituents were present in the ripe pulp.Peel colour and pulp texture were both found to be useful indices of the stage of ripeness of the pulp after harvest. Changes in these physical parameters correlated well with the starch and sugar content of the pulp, irrespective of the rate of ripening.     

青香蕉微波干燥中淀粉糊化行为及消化特性的研究

明确微波干燥(Microwave drying,MD)过程中青香蕉水分迁移与其淀粉糊化行为的关系及其对淀粉消化特性的作用,以青香蕉片为研究对象,设计不同微波功率密度,研究青香蕉MD干燥特性、淀粉糊化行为及消化特性的变化.结果表明微波功率密度和MD时间对青香蕉中淀粉糊化行为和消化特性影响显著.当青香蕉含水率高于45％,在...     

不同品种烤烟成熟期糖代谢酶活性及基因的表达分析

为了探究不同品种烤烟成熟期糖代谢的变化规律,明确烟叶品质形成的分子作用机理。以烤烟品种秦烟96、豫烟6号和K326为试验材料,测定分析了烤烟成熟期水溶性糖组分（葡萄糖、果糖、麦芽糖、蔗糖、还原糖和可溶性总糖）含量、糖代谢关键酶活性及基因表达的变化。结果表明,3个品种烤烟水溶性糖组份含量变化趋势基本一致,各水溶性糖（蔗糖除外）含量呈先升高后降低的变化趋势,烟叶成熟时其含量达到峰值;蔗糖含量呈双峰波动,烟叶成熟时蔗糖含量较低。烟叶打顶至适熟阶段,SPS和AI酶活性对烟叶中水溶性糖的积累贡献最大,NtINV对烟叶糖代谢起主要调控作用;当烟叶由适熟至过熟时,AI酶活性主要参与烟叶糖代谢活动,而SS和SPS则对蔗糖积累起重要作用,NtSS和NtSPS对烟叶糖代谢起主要调控作用。同一生态环境和栽培条件下,豫烟6号内含物质充实,具有较高的水溶性糖分含量,SPS和AI酶活性的差异可能是造成烟叶糖组分及含量不同的重要原因。     

Effect of maturity on some biochemical changes during ripening of banana (Musa sapientum L. c. v. Lakatan)

The starch, total sugars, titratable acids and total soluble solids of ‘Lakatan’ bananas picked at two different stages of maturity were determined during ripening at 23·3°C. Fruits picked at maturity stage A (between ‘full’ and ‘full three-quarters’) showed parallel trends in biochemical changes with those picked at maturity stage B (between ‘full three-quarters’ and ‘light full three-quarters’). However, stage A fruits ripened sooner than stage B fruits. The former required 13 days to ripen, whereas the latter took more than twice as long (29 days).Starch increased to a peak at the initial stages of ripening but decreased thereafter. Titratable acids increased, accompanied by a rapid decrease in starch, before the eating-ripe stage was reached. Total sugars and total soluble solids remained low until the final stages of ripening, when a rapid increase in these constituents was observed.Based on the sugar-to-acid ratio, the quality of the ripened fruits was comparable.     

RESPONSE OF BANANAS AND PLANTAINS TO IMPACT FORCES

Banana and plantains were obtained at green firm stage and stored at 20C and 90% relative humidity for up to 11 days. Some of the fruits were removed each day from storage and subjected to three impact energy levels (0.206, 0.514 and 0.828 J) using a specifically designed impacter. The impacted fruits were incubated at the same storage conditions for 24 h before assessing the bruise volume. Two models relating the bruise volume, the impact energy and the storage time were developed for both fruits. For bananas, the bruise volume had a linear relationship with the energy absorbed by the fruits, whereas the relationship was nonlinear for plantains. Plantains seemed to sustain less bruise volume than bananas during the initial storage period, but their bruise volume increased much faster in the subsequent storage days than bananas.