Kinetics of ascorbic acid degradation in un-pasteurized Iranian lemon juice during regular storage conditions

The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 +/- 3 degrees C) and in the refrigerator (3 +/- 1 degrees C). Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method in the presence of 2,6-dichlorophenol indophenol. The study was carried out for 12 weeks after which slight changes in color, taste and apparent texture in some samples were observed and ascorbic acid content reduced by 50%. Soluble solids content, pH value and total acidity were 5.5 degrees Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly influenced by storage time or conditions. Ascorbic acid content initially at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the first three weeks of storage. The final ascorbic acid content of all samples was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in the juice at all conditions followed a first-order kinetic model with activation energy of 137 cal mol(-1).     

Chemical characterization of high-yielding varieties of cashew (Anacardium occidentale)

Cashew apples and kernels from sixteen high-yielding varieties were chemically characterized. Protein, starch, amino acids and sodium contents in cashew kernels did not vary significantly among the high-yielding varieties. Reducing sugar content in the kernel was negligible compared to total sugar. Ascorbic acid, amino acid, phenol and tannin contents in cashew apple showed a significant variation among high-yielding varieties. Non-reducing sugar content in cashew apples was negligible. Varieties M 6/1, Bla 256-1, M 10/4 and M 44/3 appeared to be better for apple juice extraction because of their low tannin content. No varietal difference was noticed with respect to qualitative composition of sugars, organic acids and phenols.CPCRI Contribution No. 459     

Post harvest physiconutritional changes in Kagzi limes (Citrus aurantifolia Swingle) treated with selected oil emulsions and diphenyl

Influence of oil emulsions and diphenyl on post-harvest physico nutritionalchanges in Kagzi limes (Citrus aurantifolia) was studied. During twelvedays of storage, physiological loss in weight (PLW) and rotting were at a minimum in fruits treated with Neem (Azadirachta indica A. Juss.) oilplus diphenyl; juice content was at a maximum in mustard oil + diphenyltreated fruits. With the advancement of storage period, total soluble solidswere increased while ascorbic acid and acidity of fruits decreased. Mustardoil plus diphenyl supported maximum ascorbic acid (25.60 mg/100 ml juice) andminimum total soluble solids (9.03%).     

The suitability of African bush mango juice for wine production

A good quality wine was produced from African bush mango (Irvingia var.gabonensis). Analysis of the African bush mango juice showed that it contained 3.6% total sugar, 1.09% protein, 4.2° Brix soluble solids (SS) 0.5% ash, 50.24% total solids (TS), 66.7 mg/100 ml ascorbic acid and pH 5.12. The juice ameliorated to 23° Brix was inoculated with 3% (w/v) Baker's yeast (Saccharomyces cerevisiae) and held at 30±2°C for 28 days. SS and pH decreased while titratable acidity (TA) increased with increasing period of fermentation. Fermentation was 110% efficient. The wine produced had 8.12% (v/v) alcohol, 0.78% protein, 6.5% Brix SS, 0.64 g/100 ml TA, and a pH 3.10. Sensory evaluation results showed that there was no significant difference (p=0.05) in colour, mouthfeel, sweetness, flavour and general acceptability, between African Bush mango wine and a reference wine. The wine was generally accepted.     

Calcium chloride sprays decrease physiological disorders following long-term cold storage of apple

Field experiments were carried out at the Horticultural Research Institute, and in five commercial apple orchards, located in southwest Finland including the Åland Islands during 1994 and 1995. The experimental cultivars were Melba, Raike, Red Atlas, Åkerö, Aroma, and Lobo. The treatments were untreated control and preharvest calcium chloride (CaCl₂) sprays at Ca 2.0 g/l. Fruit samples were stored for two to six months at 2–4 °C and 85–95% RH. The percentage of the incidence of physiological disorders of stored apples was scored. Fruit macronutrients, firmness, diameter and juice titratable acidity and percentage of soluble solids were determined. Only a few nutrient effects in the flesh of the apple cultivars were a result of CaCl₂ sprayings. Preharvest CaCl₂sprays increased fruit firmness and the titratable acidity but decreased soluble solids, soluble solids/titratable acidity ratio, and the incidence of physiological storage disorders of some cultivars. When looking at the mean of all cultivars, CaCl₂ sprayings increased titratable acidity and decreased soluble solids/titratable acidity ratio after four months of storage during 1995 and reduced the incidence of physiological disorders after three months of storage during 1994 and after four months of storage in 1995.     

Preliminary studies on combiners and combinations for quality traits in tomato (Lycopersicon esculentum Mill.)

Line×Tester analysis of 2 testers and 10 lines was conducted for fruit quality characters. Though both general (gca) and specific combining ability (sca) variances contributed significantly for these traits, the contribution of sca variance was more prominent for titratable acidity, total soluble solids and ascorbic acid content, while for pericarp thickness gca variance was more important. The highest gca effects for pericarp thickness, total soluble solids, ascorbic acid content and titratable acidity were recorded by the lines SM, Sioux, TT and SW 72, respectively. Based on pooled gca score, SW 72 was recognised as a good combiner for quality traits. The magnitude and significance of sca effects varied with the characters. Two superior crosses were identified and the implication of combining ability effects on handling these crosses are discussed.     

腰果梨酒的果香保持作用研究

应用气相色谱分析方法,研究腰果梨酒的果香保持作用,结果表明,腰果梨汁中高含量的抗坏血酸和多酚有利于保持腰果梨酒的原果香。     

The storage effects of calcium-fortified orange juice concentrate in different packaging materials

Orange juice concentrate has been fortified with calcium in order to fulfil part of the recommended daily allowance of calcium and to overcome the problem of the shortage of milk and dairy products in Egypt. The loss of quality of calcium-fortified and unfortified orange juice concentrate was evaluated in three different packaging materials and when stored for ten weeks at room temperature. The results showed that vitamin C content decreased during storage for both the fortified and the unfortified samples. The trend of ascorbic acid breakdown was similar in all packaging treatments. The total titratable acidity declined during storage period; however, the decline was higher in the unfortified sample than in the fortified one. Also, the pH values increased along with the storage period. The results illustrated that the color values of both the fortified and unfortified diluted orange juice concentrate changed little at the end of the storage period. However, the samples packaged in low density polyethylene bags had the higher orange in the color values R and Y. The changes in the iron content for both samples was negligible during the storage period. However, a very slight change in the calcium content (4.5% and 4%) was observed after ten weeks of storage for both the unfortified and the fortified samples respectively. The acceptability of fortified orange juice rated higher than the unfortified one. The panelists' evaluation values were affected by the packaging treatment and storage time. The samples packaged in low density polyethylene bags had a higher level of decline of the panelists' evaluations than the ones packaged in laminated pouches or cans, while the latter had a lower level of decline.     

Alcohol production in submerged cashew pomace

The variations in the total titratable acidity, hydrogen ion concentration, reducing sugar, soluble solids and alcohol contents of the supernatant of the submerged cashew pomace in a non-aseptic condition were investigated. The crude fibre content of the pomace was also determined during fermentation. At intervals, the changes in microbial load in both the pomace and its supernatant were examined during the 14-day study. Fifty four percent of the total soluble solids (TSS) was utilised within 7 days of degradation while an increase of about 91% in the total titratable acidity occurred in the cashew pomace within the same period bringing its pH to 3.24. Acid hydrolysis of the pomace accounted for the relative high value of 2.15% TSS on the 8th day. Isolates of the generaLeuconostoc, Lactobacillus, Pediococcus, Aspergillus, Rhizopus and some yeast strains were obtained from the fresh pomace. The fungal colonies constituted about 76% of the population in the cashew pomace. The 86% drop in microbial population of the 8th day biodegraded pomace could be attributed to a decrease in nutrients of the substrate and the inhibitory effect of the organic acids produced during fermentation.     

Biochemical Properties of Red Currant Varieties in Relation to Storage

Eleven red currant varieties (Ribes rubrum L.) cultured in Serbia were evaluated for some of their biochemical properties such as total phenolics, anthocyanins, ascorbic acid, invert sugar, soluble solid content, and acidity. The average amount of ascorbic acid varied from 50.5–71.6 mg/100 g FW, while concentration of invert sugars ranged from 6.0%–9.0%. The highest amounts of total phenolics and anthocyanins were detected in variety Redpoll (153.4 mg GAE/100 g FW and 19.3 mg/100 g, respectively). Red currants were processed to juice, and the phenolic and anthocyanin contents changed as a result of processing. Berries and juices were long-term stored at −18 °C and changes in phytochemicals were monitored. In berries, storage caused the decrease of ascorbic acid content up to 49%, and a general reduction of total phenolics was also noticed. In juices, total phenolics content increased after one year of storage. In both berries and juices total anthocyanins increased during storage by up to 85% and 50%, respectively. This study demonstrates that certain varieties, namely Redpoll, Jonkheer and London Market are good source of phytochemicals, retaining the nutritional value during processing and storage.     

Studies on jicama juice processing

Juice was extracted from jicama (Pachyrrizus erosus Urban) and clarified using a 10 000 daltons molecular weight cut-off membrane to improve its stability. Ultrafiltered juice was tested for general composition and Hunter color. Ultrafiltration (UF) retentate and UF permeate showed some changes, compared to fresh juice, in total and soluble solids, total sugars, and nitrogen, whereas ash and pH remained constant. Hunter color of juice samples exhibited some variation by UF. Results suggest that UF has potential to produce jicama juice with desirable and stable aroma and flavor.     

Developmental changes in composition and quality of prickly pear cactus cladodes (nopalitos)

The composition and quality of edible tender stems or cladodes of 3 Prickly Pear Cactus species (Opuntia amyclaea, O. ficus-indica, and O. inermis) were studied at different stages of development. This traditional Mexican vegetable is called nopalitos in Spanish and cactus leaves in English. Cladodes harvested when 20 cm in length have the following average composition per 100 g: 91.7 g of water, 1.1 g of protein, 0.2 g of lipid, 1.3 g of ash, 1.1 g of crude fiber, 4.6 g of complex carbohydrates and 0.82 g of simple sugars, 12.7 mg of ascorbic acid and 28.9 µg of carotenes. The cladode's juice has an average pH of 4.6, 0.45% titratable acidity and 6.9% soluble solids. The components which varied most during development of the cladodes were: carotenes, acidity and total carbohydrates which increased, and protein and crude fiber (acid-detergent) which decreased. The nutritive value of the tender cladodes in the stages of growth at which they are commonly harvested and consumed (15 to 25 cm long weighing 50 to 80 g per stem), was similar for the 3 species.     

Preparation and fermentation of rice-defatted soy flour blends: Effect on protein,fat and ash content

Rice-defatted soy flour blends prepared in three proportions viz. 40:60, 50:50 and 60:40 were fermented with buttermilk at 25, 30 and 35°C for 12, 18 and 24h. Fermentation of these blends lowered the pH and raised the titratable acidity, maximum drop in pH and rise in titratable acidity being observed at 35°C for 24h. The fermentation either decreased or did not change the protein content of cereal-legume blends. Fat as well as ash content remained unaltered irrespective of temperature and time period of fermentation.     

Use of Banana (<Emphasis Type="Italic">Musa acuminata</Emphasis> Colla AAA) Peel Extract as an Antioxidant Source in Orange Juices

Using banana peel extract as an antioxidant in freshly squeezed orange juices and juices from concentrate was evaluated. Free radical scavenging capacity increased by adding banana peel extracts to both types of orange juice. In addition, remarkable increases in antioxidant capacity using 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical were observed when equal or greater than 5 mg of banana peel extract per ml of freshly squeezed juice was added. No clear effects were observed in the capacity to inhibit lipid peroxidation. Adding 5 mg banana peel extract per ml of orange juice did not substantially modify the physicochemical and sensory characteristics of either type of juice. However, undesirable changes in the sensory characteristics (in-mouth sensations and colour) were detected when equal or greater than 10 mg banana peel extract per ml of orange juice was added. These results confirm that banana peel is a promising natural additive that increases the capacity to scavenge free radicals of orange juice with acceptable sensory and physicochemical characteristics for the consumer.     

Evaluation of the Biochemical Components and Chromatic Properties of the Juice of <Emphasis Type="Italic">Vaccinium macrocarpon</Emphasis> Aiton and <Emphasis Type="Italic">Vaccinium oxycoccos</Emphasis> L.

Benzoic acid, total anthocyanins, soluble solids, titratable acidity, and colour properties in juice of the American cranberry Vaccinium macrocarpon and the European cranberry Vaccinium oxycoccos were investigated. Berry juices of V. macrocarpon cultivars were distinguished by their higher total anthocyanin and benzoic acid amounts. These cultivars accumulated on average 43.11 mg/l of benzoic acid and 92.45 mg/l of total anthocyanins. The levels of benzoic acid and total anthocyanins in V. oxycoccos cultivars were 17.52 mg/l and 42.54 mg/l, respectively. The V. macrocarpon cultivars ‘Franklin’, ‘Le Munyon’, ‘Searles’, and ‘Early Richard’ were selected as the best according to the enhanced total anthocyanins and benzoic acid amounts. The separation of anthocyanins by HPLC-UV-VIS revealed the presence of six anthocyanins, with peonidin-3-galactoside being the most prevalent. Galactoside together with glucoside conjugates comprised the largest percentage of total anthocyanins in the juices of V. macrocarpon and V. oxycoccos cultivars.     

不同浓度40%溴酰·噻虫嗪SC灌根处理对苹果绵蚜防控效果评价

为明确不同浓度40%溴酰·噻虫嗪SC对苹果绵蚜的田间防效及苹果品质的影响,2018年在云南昭阳区苹果主产区果园,采用以清水灌根为对照,40%溴酰·噻虫嗪SC 500倍液、750倍液、1000倍液在落花期至幼果形成期灌根处理进行防控苹果绵蚜效果评价。结果表明,3个浓度的40%溴酰·噻虫嗪SC溶液均可持续降低苹果绵蚜虫落数,增加虫口减退率,对苹果绵蚜均有较好较长的防效,其中750倍液40%溴酰·噻虫嗪SC对绵蚜防效最好,500倍液和1000倍液的防效次之;品质分析表明,40%溴酰·噻虫嗪SC处理可增加苹果可溶性固形物和可溶性蛋白含量,而可溶性糖、可滴定酸和维生素C含量显著降低。从降低农药施用量及保证苹果品质出发,生产中建议以750倍液、1000倍液40%溴酰·噻虫嗪SC防治苹果绵蚜为佳。     

Shelf life study of some Nigerian fruit juices inoculated with ascospores ofNeosartorya spp.

Mango, orange and pineapple juices containing various concentrations of sucrose were dispensed in 100 ml volumes into 100 ml conical flasks with stoppers. Each juice in a flask was inoculated with ascospores of one local isolate of eitherNeosartorya fischeri, N. fischeri var.spinosa orN. quadricincta to a final concentration of 120–140 ascospores/ml of juice, and then pasteurized at 80°C for 30 min. A set of 36 inoculated flasks with 12 controls was stored at 4–5°C and two sets, one protected with 100 mg/l sodium benzoate, were stored at room temperature (25–28°C). A shelf life study was carried out on all the juices for 64 days. Only fruit juices stored at 4–5°C and those containing sodium benzoate stored at room temperature were protected from spoilage by these fungi for 64 days. Addition of sucrose at levels of 9% to mango juice, 30% to pineapple juice and 31.5% to orange juice significantly (p=0.05) protected ascospores from inactivation during cold storage.     

Color and Antioxidant Characteristics of Some Fresh Fig (Ficus carica L.) Genotypes from Northeastern Turkey

Fruit skin color, total phenolics, total anthocyanins, soluble solids content, titratable acidity and total antioxidant capacity in fresh fruits of a number of local and well-known fig (Ficus carica L.) genotypes and cultivars grown in northeastern Turkey were determined. TEAC (Trolox equivalent antioxidant capacity) and FRAP (ferric reducing antioxidant power) assays were used to determine total antioxidant capacity. Fruit skin color of genotypes were found to be very diverse, i.e., light green, light purple, purple, dark purple and black. The content of total phenolics, soluble solids content (SSC) and titratable acidity greatly varied in the range from 24 to 237?mg of gallic acid equivalent per 100?g fresh weight, 18.60 to 26.30?% and 0.16 to 0.47?% in local genotypes and studied cultivars. In general, total antioxidant capacities determined by two methods expressed higher values in the local fig genotypes compared with the cultivars. The results suggested that genotype is the main factor that determines difference in the composition of bioactive compounds in figs and provide information on putative health benefits locally grown genotypes.     

套袋时期对‘立冬本’龙眼果实生长发育和品质的影响

以福建省晚熟龙眼品种'立冬本'果实为材料,研究果实采前套袋时期(盛花后80、95、110d)对龙眼果实生长发育、外观品质及果肉内在品质的影响.结果表明:果实采前套袋时期越早,则落果率越高;果实采前3个不同套袋时期都可以增加果实纵径、横径和单果重,提高果皮叶绿素、类胡萝卜素、花色素苷和类黄酮含量,以及果肉的可溶性固形物、总糖、维生素C和可溶性蛋白质等营养物质含量,降低可滴定酸含量.综合研究结果认为.'立冬本'龙眼果实的最佳套袋时期为盛花后110d.即果实采收前1个月左右.     

Vitamin C Enrichment of Fruit Juice Based Ready-to-Serve Beverages Through Blending of Indian Gooseberry (<Emphasis Type="Italic">Emblica officinalis</Emphasis> Gaertn.) Juice

Physiconutritional qualities of fruits viz. apple, lime, pome- granate, Perlette grape, and Pusa Navrang grape were analyzed and compared with those of Indian gooseberry (Emblica officinalis Gaertn.). Indian gooseberry juice contained the highest vitamin C (478.56 mg/100 ml). Hence, when gooseberry juice was blended with other fruits juice for the preparation of ready-to-serve (RTS) beverages, it boosted their nutritional quality in terms of vitamin C content. On the basis of overall sensory quality and vitamin C content, RTS beverage prepared by blending gooseberry and Pusa Navrang grape juice in 20:80 ratio was found to be the best.