Effect of storage conditions on the chemical attributes of Ogbomoso mango juice

Mango juices were extracted from Ogbomoso variety using the method of Brekke et al. (1972). Mango juices were packaged in polyethylene films, polyethylene tetraphthalate (PET or plastic) bottles and transparent glass bottles and stored at 6 °C, 26 °C and 34 °C. Percentage ascorbic acid loss, browning index, titratable acidity, pH and soluble solids were evaluated at 2-week intervals for 8 weeks. Percentage ascorbic acid loss, non-enzymatic browning and titratable acidity increased with storage time in all packaging materials. However, pH decreased with storage time and soluble solids remained constant. Higher percentage ascorbic acid loss, browning index and titratable acidity occurred in juices packaged in polyethylene film, than in PET and glass bottles. Percentage ascorbic acid, browning index and pH increased with increased storage temperature. However, titratable acidity decreased with increased storage temperature and soluble solids remained constant throughout the period of storage.     

Effects of sucrose polyester coating on fruit quality of apricots (Prunus armenaica (L))

Mature apricots were coated with different concentrations of a mixture containing sucrose polyesters (Semperfresh(tm) fruit coating) to determine the effect of that coating on shelf-life, post-storage life and quality of apricots. Respiration rates, weight loss, colour change, variations in soluble solids, ascorbic acid content, titratable acidity and pH of apricots were effectively reduced by both the 10 g litre^?1 and 15 g litre^?1 concentrations during ambient storage. After 10 days of cold storage both concentrations caused firmer fruit, higher pH, titratable acidity, soluble solids and ascorbic acid.     

Effects of Chitosan on Yield and Compositional Data of Carrot and Apple Juice

Effects of chitosans on yield, titratable acidity, pH, soluble solids, and color of carrot and apple juice were evaluated. Carrots (Lange Rote Stumpfe) and apples (Golden Delicious) were treated with chitosan solutions (in 2% ascorbic acid) of two different concentrations and viscosities at 25°C between 0 and 120 min. The juices were obtained with a laboratory cage press following a standard program during 20 min. Treatments with chitosan produced no effect on juice yield but pH values and soluble solids were affected. Also chitosan treatment resulted in significant (P < 0.05) reduction of titratable acidity and color index. Reduction of β-carotene in carrot juice was also achieved and correlated with color index.     

A COMPARISON OF FRUIT OF HIGHBUSH AND RABBITEYE BLUEBERRY CULTIVARS1

In 1986, 1988 and 1989, fruit from highbush blueberry (Vaccinium corymbosum L., cvs Collins, Bluecrop, and Herbert) and rabbiteye blueberry (V. ashei Reade, cvs Climax, Tifblue, and Menditoo) grown at the same location were compared for size, raw product quality, storage, and sensory attributes. Compared with rabbiteye blueberry fruit, fruit of highbush cvs were generally larger in size, volume, and surface area and higher in titratable acidity, higher Hunter color attributes of ‘L’, ‘a’, ‘b’, and chroma, protein, P, Ca, Mg, Mn, Fe, Cu, B (dry wt. basis), and higher in decay and water loss after 3 weeks storage at 7 C. Rabbiteye fruit, compared with highbush fruit, were generally higher in pulp pH, percent soluble solids, percent dry matter, seed weight per fruit, weight per seed, fruit height/width ratio, periderm dry weight per fruit, periderm wt. per surface area (in mg/cm²), sugar:acid ratio, firmness (as shear), and in sensory seediness. Fruit soluble solids, dry matter, hue, titratable acidity, pulp pH, and firmness of both species were influenced by weather (years).     

发酵型香蕉复合果汁饮料的研制及营养成分研究

以香蕉、芒果、六堡茶汤为主要原料,佰生优益生菌果蔬酵素发酵菌为菌种,研制发酵型香蕉复合果汁饮料,通过单因素和响应面试验确定最优发酵工艺条件,并对其可溶性固形物、蛋白质等营养活性成分含量变化情况进行研究。结果表明：最佳发酵工艺条件为香蕉浆50%,芒果汁5%,白砂糖添加量6%、佰生优益生菌果蔬酵素发酵菌接种量0.04%、茶汤添加量5.0%,发酵时间5.0 d,发酵温度34 ℃,此条件下得到的饮料色泽淡黄透亮、具有香蕉和芒果固有的浓郁香味,酸甜适中,其可溶性固形物、可滴定酸度、蛋白质、总糖、总多酚的含量分别为16.80%、1.20 g/kg、10.90 mg/100 g、9.91 g/100 g、0.38 mg/mL。其中总糖和总多酚在整个发酵过程中变化较小,处于稳定状态,而可滴定酸度、蛋白质呈明显上升状态,可溶性固形物变化不稳定,总体呈上升趋势。     

Effect of an Edible Nanomultilayer Coating by Electrostatic Self-Assembly on the Shelf Life of Fresh-Cut Mangoes

This work aims at evaluating the effect of an alginate-chitosan nanomultilayer coating, obtained by electrostatic layer-by-layer self-assembling, in the quality and shelf life of fresh-cut mangoes. Coated and uncoated fresh-cut mangoes were stored under refrigeration (8 °C) for 14 days. The changes in mass loss, titratable acidity, pH, ascorbic acid content, total soluble solids, malondialdehyde content, browning rate, and microbial count were evaluated during storage. At the end of the storage period, lower values of mass loss, pH, malondialdehyde content, browning rate, soluble solids, microorganisms’ proliferation, and higher titratable acidity were observed in the coated mangoes. The nanomultilayer coating did not improve the retention of vitamin C during storage of fresh-cut mangoes. Results suggest that chitosan-alginate nanomultilayer edible coating extends the shelf life of fresh-cut mangoes up to 8 days.     

RELATIONSHIPS OF COLOR, VISCOSITY, ORGANIC ACID PROFILES AND ASCORBIC ACID CONTENT TO ADDITION OF ORGANIC ACIDS AND SALT IN TOMATO JUICE

Malate and citrate acidified juices produced statistically similar results for pH and titratable acidity (TA), but these acidified juices were significantly different from nonacidified juice when comparing pH and TA. During storage time, the pattern of the pH and TA curves, regardless of acidification, were similar. Salted juice exhibited a significantly higher ascorbic acid content and greater viscosity than did the unsalted juice during storage. The organic acids citric, lactic, malic, and pyrocarboxylic increased immediately after heat processing for commercial sterility, while the presence of salt in this juice lowered these same organic acids. There was minimal correlation of the organic acids or the summation of the acids equivalents of all the organic acids to the titratable acidity or pH of the juices. Juices acidified with malate or citrate did not consistently display an increased level of that specific acid after processing and storage.     

EFFECTS of SEMPERFRESH and JONFRESH FRUIT COATINGS ON POSTSTORAGE QUALITY of "SATSUMA" MANDARINS

Mandarins were coated with Semperfresh^TM and Jonfresh^TM edible coatings. the weight gain of mandarins after application of Jonfresh and Semperfresh coatings was 0.8% and 0.6% respectively. Weight loss, respiration rate, ascorbic acid, soluble solids (brix) and acidity changes of coated mandarins were compared with uncoated mandarins during storage at 20C and 40% RH for 4 weeks. Semperfresh^TM and Jonfresh^TM coatings delayed the ripening of mandarins. Both of the coatings were effective to reduce the change of ascorbic acid, soluble solids, titratable acidity and respiration rate. But Jonfresh^TM was determined to be most efficient coating for reduction of weight loss.     

不同包装方式对芒果低温模拟运输贮藏中品质及代谢的影响

为评估商业包装(保鲜纸、塑料网套)与其他包装方式(葫芦膜、充气袋)对芒果运输过程中的保护效果,依托振动台对越南青芒在13?℃、180?r/min下进行24 h模拟运输实验,研究运输后芒果在13?℃下贮藏20 d过程中转黄率、病情指数、质量损失率、水分含量与分布、硬度、原果胶与可溶性果胶含量、呼吸强度、1-氨基环丙烷-1...     

Effects of post-harvest handling on quality attributes of tomatoes in the Nigerian marketing system

Changes in ascorbic acid and other quality attributes of fresh ripe tomatoes transported from the production areas in northern Nigeria to an urban wholesale market in south-western Nigeria were investigated. Reduced ascorbic acid concentration was lower, by as much as 35%, and dehydroascorbic acid concentration higher in damaged tomatoes relative to the undamaged control. Damaged tomatoes had a higher pH but lower total solids, soluble solids and titratable acidity than the undamaged fruits. pH and titratable acidity, as per cent citric acid, ranged from 4·06 and 0·453, respectively for undamaged tomatoes to 4·34 and 0·330, respectively for fruits with signs of bacterial and fungal rots. Total solids and soluble solids ranged from 6·12% and 5·32%, respectively for undamaged fruits to 5·39% and 4·34%, respectively for bruised tomatoes.     

SHELF-LIFE OF FRESH-LIKE READY-TO-USE DICED SQUASH

The shelf-life of fresh-like ready-to-use diced squash during storage for 16 days at 10–12C and 95% of relative humidity was investigated. The ascorbic acid (AA) content, moisture, soluble solid content, titratable acidity, pH, weight loss and microbiological counts were determined. At the end of storage, a 1.5% weight loss was observed. Water content did not show significant changes during storage. The soluble solids content and the Brix/titratable acidity ratios increased during storage, following a linear correlation. The evolution of AA content followed a 2° polynomial correlation, with a maximum between 7–9 days of storage and a final value of 17 mg AA/100 g of fresh weight. The total microbial count increased continuously throughout storage but showed an acceptable level until day 10.     

复合菌株对采后芒果品质和抗病性的影响

以实验室分离得到的汉逊德巴利酵母（Debaryomyces hansenii,Y-1）、尼泊尔德巴利酵母（Debaryomyces nepalensis,T18）和萎缩芽孢杆菌（Bacillus atrophaeus,TE-7）为材料,研究单独处理（Y-1、T18、TE-7）和复合处理（Y-1＋TE-7、Y-1＋T18、T18＋TE-7）对芒果贮藏品质和抗病性的影响。结果表明：Y-1和TE-7菌悬液以体积比1∶1复配后浸泡芒果20 min,能显著抑制胶胞炭疽菌（Colletotrichum gloeosporioides）孢子萌发;此外,与Y-1和TE-7单一处理相比,Y-1＋TE-7处理能有效延缓果实a*值、可溶性固形物质量分数、硬度、可滴定酸质量分数的变化;贮藏中后期（6 d后）,Y-1＋TE-7处理较Y-1和TE-7单一处理过氧化物酶、苯丙氨酸解氨酶、β-1,3-葡聚糖活力增强;贮藏中期（9～18 d）,Y-1＋TE-7处理较Y-1和TE-7单一处理多酚氧化酶活力减弱。说明Y-1和TE-7复合使用能显著提高采后芒果的贮藏品质,增强果实的抗病性,在芒果采后处理上具有一定的应用潜力。     

EFFECT OF SOLUBLE SOLIDS AND TEMPERATURE ON ASCORBIC ACID DEGRADATION IN LEMON JUICE STORED IN GLASS BOTTLES

Lemon juice at concentrations of 9°, 20°, 30°, 40° and 50°Brix was stored at 10°, 20° and 36°C for 16 weeks and sampled regularly for total soluble solids (TSS), pH, titratable acidity and ascorbic acid. No significant differences were found in the first two of these factors as a function of storage time. There was a small but significant decrease in citric acid concentration over 16 weeks. Ascorbic acid loss was greater at higher temperatures; at a constant temperature, the loss was smaller as TSS increased. Ascorbic acid degradation data fitted zero-, first- and second-order models equally well at all five TSS. Rate constants in 9°Brix juice were significantly higher than those for the other four concentrations at all three temperatures. E_a values of 47.8 and 24.1 kJ mol^?1 were calculated for ascorbic acid degradation in 9° and 20°Brix juices. The effect of temperature far outweighed the effect of TSS on ascorbic acid degradation. Over the 16-week storage period, maximum retention of ascorbic acid (95.7%) was obtained in the 50°Brix lemon juice concentrate stored at 10°C.     

SENSORY QUALITY AND NUTRIENT COMPOSITION OF THREE HAWAIIAN FRUITS TREATED BY X-IRRADIATION

Papayas, rambutans, and Kau oranges were irradiated at 0 (control) and 0.75 (irradiated) kGy and stored for 2 and 9 days to determine the effect of X‐irradiation on objective and sensory quality attributes. Irradiation at 0.25 kGy, as a minimum dose, has been approved as a quarantine treatment for the export of tropical fruits grown in Hawaii. The effects of irradiation and storage on specific sensory attributes were dependent on the specific fruit. Aroma and flavor tended to be more intense in the irradiated fruit. Firmness decreased as a result of irradiation and storage, though significant only in rambutans. The color of the rambutans and oranges were significantly affected by irradiation. Irradiation did not contribute to significant changes in the ascorbic acid and carotenoid contents, pH, titratable acidity, and total soluble solids. Adaptation of X‐ray irradiation as a quarantine treatment should enhance the marketability of tropical fruits.     

Classification of commercial apple juices based on multivariate analysis of their chemical profiles

Currently, a wide range of differently processed apple juices is available on the market. In this study the quality of commercial apple juices from four product categories was evaluated on the basis of their chemical profiles (total soluble solids, pH, titratable acidity, ratio of soluble solids to acidity, sugars, total phenolics content, and antioxidant activity) using multivariate methods. Principal component analysis has revealed, that the chemical parameters, such as titratable acidity, ratio of soluble solids to acidity, and pH (PC1) and sugars and total soluble solids (PC2) appears to be the parameters most differentiating the samples. Five classes of juices with similar chemical composition were detected using hierarchical cluster analysis. The exploratory analysis of the overall chemical profiles revealed that the juices clear from concentrate, cloudy not from concentrate and freshly squeezed, were easily distinguishable due to their unique properties. In contrast, cloudy juices from concentrate showed properties similar to juices of other classes. The classification based on k-nearest neighbors method had high sensitivity and low classification error for clear juices from concentrate and cloudy not from concentrate. The classification failed for the cloudy juices from concentrate.     

Postharvest application of 1-Methylcyclopropene modulates fruit ripening, storage life and quality of 'Tegan Blue' Japanese plum kept in ambient and cold storage

The role of postharvest application of 1-Methylcyclopropene (1-MCP) in modulating 'Tegan Blue' Japanese plum fruit ripening and quality under ambient and cold storage conditions was investigated. 1-MCP-treated fruit (0, 0.5, 1.0 and 2.0 μL L⁻¹) were allowed to ripen at ambient temperature in Experiment 1, while in the second experiment the fruit were kept in cold storage (0, 3 and 6 weeks) before ripening. In both experiments, 1-MCP treatment significantly delayed (2–8 days), suppressed (30–70%) the climacteric ethylene production, maintained higher fruit firmness (34–60%), titratable acidity, L* , chroma, hue angle of fruit skin and pulp, and reduced concentrations of soluble solids, ascorbic acid, total carotenoids and total anti-oxidants as compared to the control. 1-MCP (1.0 μL L⁻¹) treatment suppresses and delays the climacteric ethylene production with acceptable fruit quality during ripening at ambient temperature and is effective in extending the storage life up to 6 weeks with minimal loss of plum fruit quality.     

6个芒果品种品质特性评价研究

对台农一号、紫花、桂七、凯特、马切苏和三年芒6个品种芒果原浆的色泽、口感滋味及物理特征进行了评价,分析了包括可溶性固形物、可滴定酸度、pH、总糖、胡萝卜素、抗坏血酸、黏度以及色泽等与芒果原浆品质特性相关的物理和生化指标。基于SPSS统计分析软件对测定指标进行了因子分析,比较了不同芒果品种品质特性的差异性,并与国外优良品种品质进行比较。结果表明,台农一号、凯特、马切苏口感品质较为适宜,马切苏和三年芒营养素含量最为丰富,凯特和紫花色泽品质较佳。中国芒果品种整体品质低于国外品种。     

Effect of sonication on orange juice quality parameters during storage

Freshly squeezed orange juice was sonicated at various amplitude levels (40%, 70%, 100%), treatment times (2, 6 and 10 min) at a constant frequency of 20 kHz. Samples were stored for periods of up to 30 days at 10 °C. The combined effect of amplitude level, treatment time and storage period on pH, ^oBrix, titratable acidity, colour values ( L* , a* , b* ), non-enzymatic browning (NEB), cloud value and ascorbic acid content were investigated. Second order polynomial models were employed to investigate the effect of independent variables. No significant differences ( P <  0.05) in ^oBrix and titratable acidity were observed. Significant changes were observed in juice pH and colour values. During storage NEB increased while both cloud value and ascorbic acid content decreased. Predictive models developed for colour values, cloud value, NEB and ascorbic acid content were highly significant and were closely correlated to experimental data. Degradation mechanisms are proposed for the key quality parameters.     

Analysis of sugars and organic acids in ripening mango fruits (Mangifera indica L. var Keitt) by high performance liquid chromatography

The sugars and organic acids present in the pulp of Keitt mangoes at various stages of ripeness were analysed by h.p.l.c. Ripening was associated with a loss in firmness, peel chlorophyll and pulp acidity, with increasing soluble solids and total sugars. The major sugars were identified as glucose, fructose and sucrose. All three increased during ripening; sucrose was found to be in the greatest concentration throughout, with fructose the predominant reducing sugar. Acidity loss was shown by decreasing titratable acidity and increasing pH values. Citric and malic acids were found to be the major organic acids. A large decrease in citric acid and a small reduction in malic acid were responsible for the loss of acidity. Tartaric, ascorbic, oxalic and α-ketoglutaric acids were also shown to be present at low concentrations.     

CONTROLLED ATMOSPHERE STORAGE AND EDIBLE COATING EFFECTS ON STORAGE LIFE AND QUALITY OF TOMATOES

Tomatoes at pink stage maturities were coated with Semperfresh^TM edible fruit coating which is composed of sucrose esters of fatty acids, sodium carboxymethyl cellulose and mono-diglycerides of fatty acids. One group of coated and uncoated tomatoes were stored at 23 × 2C under air atmosphere, another group was stored at 12C under air atmosphere and third group was stored at 12C, 93–95% RH in a controlled atmosphere (CA) containing 3% CO₂, 3% O₂ and 94% N₂. Samples of tomatoes were analyzed for firmness, weight loss, titratable acidity, pH, soluble solids, sugars, ascorbic acid and lycopene to examine changes in quality during storage. Semperfresh^TM edible fruit coating was found to be significantly effective at both storage temperatures (23 × 2C and 12C) in air to delay changes in firmness, titratable acidity, pH, soluble solids, sugars, ascorbic acid and lycopene. Semperfresh^TM fruit coating reduced fruit weight loss as compared to fruit without coating but the difference between coated and uncoated tomatoes was not significant. Shelf-life of pink tomatoes was increased 3 days at 23 × 2C and 6 days at 12C in air by coating. CA storage delayed compositional changes in tomatoes significantly as compared to air storage of coated and uncoated tomatoes. CA storage also had a significant potential for reducing weight loss and microbial spoilage. Tomatoes were stored 40 days in CA. Coated and uncoated tomatoes exhibited the same results in CA.