RIPENING AND QUALITY CHANGES IN MANGO FRUIT AS AFFECTED BY COATING WITH AN EDIBLE FILM

Mango fruit has a relatively short storage life of about 2 to 3 weeks at 13C. In order to prolong the storage life of ‘Haden’ mangoes, fruit were coated with 3 concentrations (8,16 and 24 g.L^?1) of the edible coating film “Semperfresh” and then stored at 13C and 85% RH. Fruit were then evaluated every 4 days for up to 32 days for total soluble solids (TSS), titratable acidity (TA), pH, firmness, weight loss, color of the skin, and ascorbic acid content. All 3 concentrations applied to the fruit affected fruit ripening. TA, firmness, and green color were higher in coated fruit, and weight loss, SST, and pH were lower compared with the noncoated fruit. “Semperfresh” had no effect on decay development. Ascorbic acid decreased in all stored fruit, but this decrease was slower in coated fruit, and there were no significant differences between the different “Semperfresh” concentrations.     

Effect of calcium on the storage life of oro (Antiaris africana)

The effects of calcium on the ascorbic acid, chlorophyll, titratable acidity and texture (firmness) of stored oro (Antiaris africana (Mill)) friuits (average weight 100 g ) were studied. Three groups of the fruits were dipped in 20 g litre^?1, 40 g litre^?1 CaCl₂ solutions and deionised water respectively for I0 min. The fourth group, which was untreated, served as the control and was also packaged in heat-sealed cellophane bags. The fruits were displaced and stored at ambient temperature (28 ± 2°C). The calciumtreated fruits which kept better were firmer and had a slight colour change (chlorophyll) which also produced a progressive increase in ascorbic acid level during storage. The titratable acidity of the fruits did not fluctuate as signijcantly as that of the untreated (control) fruits.     

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.     

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.     

The Effect of 1-Methylcyclopropene (1-MCP) on Quality and Cell Wall Hydrolases Activities of Fresh-Cut Muskmelon (Cucumis melo var reticulatus L.) During Storage

The effects of 1-methylcyclopropene (1-MCP) on quality and cell wall hydrolases activities changes in fresh-cut muskmelon fruit stored at 4?±?1 °C for 7 days were investigated. The results showed that ethylene production of the fresh-cut fruit remained constant during refrigerated storage. 1-MCP treatments delayed the loss of fresh weight and the increase in electrolyte leakage and maintained the firmness of the fresh-cut fruit. The best results are showed in the fresh-cut fruit treated with 1.0 μL L^?1 1-MCP. The use of 1-MCP had no influence on the total soluble solids (TSS) content and pH of the fresh-cut fruit which they remained constant over storage. The titratable acidity (TA) of the fresh-cut fruit decreased during storage and the sample treated with 1.0 μL L^?1 1-MCP showed the lowest data. TSS/TA ratio increased during storage and the TSS/TA ratio was lower in 1-MCP-treated samples than that for the control one. The use of 1-MCP inhibited polygalacturonase (PG), β-galactosidase (β-Gal) and β-galactanase activities, whereas the increases in these enzymes activities were found in the control. Antioxidant capacity and total phenolics content of both 1-MCP-treated and untreated samples remained constant over storage. The reduction of total ascorbic acid content was detected after 7 days of storage. The ascorbic acid content in 1-MCP-treated sample was slightly higher, although not significantly different, than that of the control after 7 days. These results suggest that the loss of firmness was the key factor affecting quality of fresh-cut muskmelon fruit and the use of 1-MCP maintained the quality and inhibited the loss of firmness by retarding the increase in electrolyte leakage and inhibiting cell wall hydrolases activities.     

Effects of sodium caseinate‐ and milk protein concentrate‐based edible coatings on the postharvest quality of Bing cherries

Bing cherries were coated with sodium caseinate‐ or milk protein concentrate‐based edible coatings. Besides the proteins (100 g kg^?1), the coating formulations also included glycerol (about 300 g kg^?1 protein) and either beeswax or a stearic–palmitic acid blend at a concentration of 0, 100 or 300 g lipid phase kg^?1 of protein. All coatings, especially those containing 300 g kg^?1 stearic–palmitic acid blend, successfully reduced water loss of the fruits. The edible coatings had a beneficial effect on the sensory quality of the cherries, and there were significant (p < 0.05) effects of the coating treatments on soluble solids, titratable acidity and pH. Copyright © 2004 Society of Chemical Industry     

不同pH值CMC涂膜对石榴果实采后生理指标及贮藏品质的影响

以陕西临潼净皮甜石榴为试材,研究了不同pH值CMC涂膜对石榴果实采后生理指标及贮藏品质的影响。结果表明:石榴在(4.0±0.5)℃条件下贮藏,采用pH值5.0、0.5%CMC溶液涂膜,能有效保持石榴籽粒可溶性固形物含量、总糖含量和可滴定酸含量,减缓果皮相对电导率和褐变指数升高速率,降低果实呼吸速率和腐烂率,抑制果皮抗坏血酸氧化酶(AAO)和多酚氧化酶(PPO)活性,保持果皮过氧化物酶(POD)活性相对较高水平。贮藏120d果实外观色泽鲜艳,籽粒感官品质良好,保鲜效果理想。     

Effects of an Edible Coating and Cold Storage on Shelf-life and Quality of Cherries

The effects of an edible coating, i.e. Semperfresh^TM and cold storage on shelf-life and quality of cherries were studied. Two groups of cherries (Prunus avium) were coated just after harvest with 10 and 20 g/L Semperfresh^TM fruit coating which is composed of sucrose esters of fatty acids, sodium carboxymethyl cellulose and mono-diglycerides of fatty acids. Half of the cherries from each of the above groups was stored at ambient temperature (∼30±3 °C) and at 40-50% relative humidity, the other half of the cherries was stored at cold storage (0 °C) and at 95-98% relative humidity. Each group was analysed for the following quality parameters: firmness, weight loss, titratable acidity, soluble solid content, sugar content, ascorbic acid content, and external color. It was demonstrated that Semperfresh^TM was effective to reduce the weight loss and increase firmness, ascorbic acid content, titratable acidity and skin color of cherries during storage time. However, soluble solid content and sugar content were not affected by coating. The results of this study suggest that Semperfresh^TM increased the shelf-life of the cherries by 21% at 30±3 °C and by 26% at 0 °C without perceptible losses in quality.     

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.     

Effects of a chitosan‐based coating with ascorbic acid on post‐harvest quality and core browning of ‘Yali’ pears (Pyrus bertschneideri Rehd.)

BACKGROUND: Chitosan (CTS), as an ideal coating material, has been used for post‐harvest treatment of fruits and vegetables. The effects of coating with 1.5% CTS, alone or combined with 10 mmol L^?1 ascorbic acid (AsA), on post‐harvest quality and core browning (CB) incidence in ‘Yali’ pears during storage at room temperature (25 ± 1 °C) were investigated in this study. RESULTS: It was found that both CTS coating and CTS + AsA coating delayed the increase of weight loss, retained greater firmness, total soluble solids and titratable acidity content than controls; coatings decreased respiration rate and membrane permeability, and also effectively inhibited CB after 60 days of storage. Compared with CTS coating alone, CTS + AsA coating increased these beneficial effects and also helped to retain a much higher AsA content and the activities of antioxidative enzymes (superoxide dismutase, catalase and ascorbate peroxidase). CONCLUSION: The CTS coating has the potential to maintain post‐harvest quality and control CB which is the main problem in ‘Yali’ pears during storage. The CTS + AsA coating has more effective application in this study, which could not only be due to reducing the respiration rate and inhibiting the senescence process, but also to increasing the antioxidant capability of the fruit. Copyright © 2008 Society of Chemical Industry     

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.     

Maturity and ripening effects on chemical and sensory properties of apple juice

The effects of harvest maturity and ripening on the chemical composition and sensory characteristics of ‘McIntosh’ and ‘Spartan’ apple juice were evaluated. Juice was extracted from fruit harvested at seven weekly intervals beginning 3–4 weeks before commercial harvest and from fruit held in air storage (1°C) for 1 to 3 months. Internal ethylene concentration and starch index were used as maturity indices. Principal component analysis of juice data (pH. titratable acidity, organic acids, soluble solids, sugars, phenols, turbidity, and Hunterlab colour) showed a distinctive maturity effect on the characteristics of juice extracted from fruit immediately after harvest or after storage. Triangle testing showed aroma and flavour differences in both ‘McIntosh’ and ‘Spartan’ to be first discernable when ethylene was first detected (internal ethylene concentration ≥ 0.1 μl litre^?1) and starch hydrolysis evident (starch index 3.0–5.0 for ‘McIntosh’, 1.5–3.0 for ‘Spartan’), or after 2–3 months of air storage. Sensory profiling of fruity aroma, total aroma, fruit flavour by mouth, sweetness, and sourness in the juices showed increased fruitiness and sweetness and decreased sourness with advancing maturity.     

Degradation of quality attributes of sweetened Julie and Ogbomoso mango juices during storage

Changes in the quality attributes of sweetened Julie and Ogbomoso mango juices were investigated. Sweetened mango juices were processed, bottled and stored at 25 °C for 12 weeks. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents were evaluated immediately after processing and subsequently at 2-week intervals. The L*, a* and b* (HunterLab) parameters were determined to evaluate colour changes due to non-enzymatic browning.Generally, the quality attributes of the sweetened mango juices decreased during storage. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents decreased during storage. After 12 weeks of storage, the percentage ascorbic acid loss of sweetened Julie and Ogbomoso mango juices was 16.25 and 16.67%, respectively. Browning index, chroma and b* values increased during storage. Colour changes in sweetened mango juices were mainly due to b* value and chroma.     

QUALITY OF FRESH-CUT TOMATOES

Tomato fruit at pink or light-red stages of ripening were cut into slices, rinsed with water containing 50 μL.L⁻¹ sodium hypochlorite and drained. They were stored in perforated polyethylene package at 1C in air or controlled atmosphere for five and ten days. Weight loss, chlorophyll and lycopene contents, seed discoloration, fungal infection, total soluble solids content, titratable acidity, sugar/acid ratio, pH, flavor and taste, firmness, ascorbic acid content, rate of respiration and ethylene production, and electrolyte leakage were evaluated after each storage period. The overall quality of controlled atmosphere-stored slices was better than that of air stored slices. Slices from light-red fruit had lower weight loss, minimum seed discoloration, lower     

Application of ATR-FTIR for a rapid and simultaneous determination of sugars and organic acids in apricot fruit

A simple, fast and accurate Fourier transform mid-infrared spectroscopy method was developed for simultaneously determining sugar and organic acid contents in apricot fruit slurries using the attenuated total reflectance. The potential of this method coupled with chemometric techniques based on partial least squares was assessed by comparison with currently used enzymatic determination of sucrose, glucose, fructose, malic acid and citric acid. Fruits of eight contrasted cultivars harvested at different ripening stages were used in this study and randomly divided in a calibration set (505 apricots) and in a validation set (252 apricots). The most suitable region was found in the range between 1500 and 900 cm⁻¹. Good prediction performances were obtained (R² ? 0.74 and RMSEP ? 18%). Results concerning the prediction of other quality traits such as firmness, skin colour, ethylene production, soluble solids content and titratable acidity were discussed.     

Pre‐ or post‐harvest applications of putrescine and low temperature storage affect fruit ripening and quality of ‘Angelino’ plum

BACKGROUND: Plum has a very short storage life. The role of pre‐ or post‐harvest applications of putrescine (PUT) and low temperature storage on fruit ripening and quality was investigated in plum fruit (Prunus salicina Lindl. cv. Angelino). RESULTS: Pre‐ or post‐harvest PUT treatments [(0.1, 1.0 or 2.0 mmol L^?1) + 0.01% Tween‐20 as a surfactant] delayed and suppressed the climacteric ethylene production and respiration rate irrespective of the method used to apply PUT. PUT‐treated fruit following low temperature storage (0 ± 1 °C; 90 ± 5% RH), at the ripe stage exhibited higher fruit firmness and titratable acidity (TA), while soluble solids content (SSC), levels of ascorbic acid, total carotenoids and total antioxidants were lower than in untreated fruit. Fruit both sprayed with PUT and stored in low temperature for 6 weeks, at the ripe stage showed reduced respiration rate, delayed changes in the SSC:TA ratio and levels of total carotenoids compared to post‐harvest PUT application. CONCLUSION: Pre‐harvest application of 2.0 mmol L^?1 PUT 1 week before the anticipated commercial harvest was more effective in delaying plum fruit ripening and can be used to extend the storage (0 ± 1 °C) life of plums for up to 6 weeks with minimum losses in fruit quality. Copyright © 2008 Society of Chemical Industry     

FRESH LINGONBERRY QUALITY AS AFFECTED BY STORAGE CONDITIONS AND PACKAGING

Freshly harvested lingonberries (Vaccinium vitis‐idaea L.) cvs Sanna and Sussi and a wild lingonberry originating from Kainuu, Finland, were stored in 0.5 L perforated/unperforated LD‐polyethylene bags at temperatures of 1/pm0.5C and 3.5/pm0.5C for 18 weeks and at 1.5/pm0.5C and 5.5/pm0.5C for 8 weeks. The total soluble solids, pH, organic acids (titratable acidity) and total anthocyanin content of the juice were determined. The mean values of soluble solids varied from 12.96 to 14.57 (°Brix), pH from 2.95 to 3.18, organic acids (as citric acid) from 1.13 to 1.73 g 100^?1 g and anthocyanins from 49.39 to 68.74 mg 100^?1 g. Soluble solids and anthocyanin contents decreased towards the end of storage. The content of organic acids decreased throughout the storage period. The effect of package perforation was not consistent. Cv. Sanna differed most from the other genotypes. The storage time for lingonberries without any noticeable deterioration was 4 weeks at 1.5/pm0.5C and 2 weeks at 5.5/pm0.5C.     

Reduction of bitterness and acidity in grapefruit juice by adsorptive processes

By choosing an appropriate adsorbent, the bitter principles (naringin and limonin) and titratable acids could be removed from grapefruit juice in varying combinations. For example, Amberlite XAD-7 removed about 63% naringin, 85% limonin and 3% titratable acids and Deacidite-FFIP removed about 20% naringin, 8% limonin and 23% titratable acids when contacted for 1 h with grapefruit juice at the rate of 20 g (dry wt) of adsorbent per litre of juice. Such treatments, applied consecutively, would eliminate excessive bitterness and acidity from juices containing up to 2 g naringin and 36 mg limonin litre^?1 and with a total soluble solids:titratable acid ratio of < 6. The adsorbents are readily available, may be used as supplied and can be reactivated simply and economically; some of them have already been approved for use with foods, and such approval seems possible for the others.     

Preservation of quinces by the combination of an edible coating material, Semperfresh, ascorbic acid and cold storage

Quinces (Cydonia oblonga, Miller) have a crucial economic value owing to their demand as jams or compote, and their high vitamin and fiber content. A preservation method for extending the shelf life of quinces by the combination of an edible coating material, Semperfresh, ascorbic acid and cold storage was designed in this study. The ascorbic acid content, firmness, total sugar, pH, titratable acidity, respiration rate, soluble solids, weight, total humidity, mold, yeast, and total mesophilic aerobic bacteria count were monitored. It was found that the triple combination of Semperfresh, ascorbic acid and cold storage provides high microbial, chemical and sensorial qualities for the quinces, leading to an extension in shelf life when compared with untreated quinces.     

百里香酚/海藻酸钠膜对茄梨贮藏品质的影响

采用海藻酸钠(Sodium Alginate,SA,2%(m/v))和百里香酚/海藻酸钠(Thymol/Sodium Alginate,Thy/SA,Thy终浓度为40 mg/L)涂膜分别对茄梨进行处理,于20℃下进行贮藏,以果实硬度、可溶性固形物含量、抗坏血酸含量、可滴定酸含量、丙二醛含量、多酚氧化酶活性等指标来判断茄梨的品质变化。结果表明,Thy/SA涂膜使得茄梨果实的贮藏期由9 d(对照组)延长至18 d,有效延缓了果实硬度、可滴定酸、抗坏血酸和总酚含量的下降,以及可溶性固形物、丙二醛含量、多酚氧化酶和过氧化氢酶活性的上升。由此可见,Thy/SA涂膜可较好地维持贮藏过程中茄梨的果实品质,进而延长了其贮藏期。