End Of Storage Life Research Articles

Characterization and antioxidant capacity of phenolic compounds of jackfruit genotypes from Nayarit, Mexico

Jackfruit is a rich source of phytochemicals, thus offering a broad perspective in developing value-added healthy nutritional foods. This research compares the content of phenolic compounds and antioxidant capacity in different jackfruit genotypes. In the results of total soluble phenols (TSP), the genotype "Agüitada" showed the highest values at the end of storage life (1.43 mg of gallic acid equivalent (GAE)/g in dry weight (DW)), as well as in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with 7.82 mmol of trolox equivalent (TE)/g DW. The "Licenciada" genotype obtained the highest ferric reducing antioxidant power (FRAP) and 2,2′-Azino-bis-(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS•+) assays values, with 244.29 and 12.08 mmol TE/g DW, respectively. Phenolic profiling by high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) quantified 28 phenolic compounds, with shikimic acid being the most abundant in all genotypes; flavonoids were also identified, with epigallocatechin standing out. The results obtained in phenolic profile, TSP and antioxidant capacity showed sufficient evidence of differences among all genotypes. This information will generate interest among consumers and will revalue this developing crop.

The role of ethylene and 1-MCP in early-season sweet cherry ‘Burlat’ storage life

Sweet cherries (Prunus avium L.) are highly appreciated because of their bioactive compound content and attractive organoleptic characteristics; however, they are very perishable. The aim of this work was to investigate whether ethylene and its antagonist 1-MCP affect the postharvest quality of an early-season sweet cherry cultivar, allowing storage life extension. ‘Burlat’ sweet cherries were subjected to three treatments at 1 °C for one month: i) control (air); ii) continuous ethylene supplementation (10 μL L−1); and iii) 1-Methylcyclopropene (1-MCP; 1 μL L−1 for 24 h) followed by air. The incidence of postharvest physiological disorders, the evolution of physical and functional quality traits, and fruit senescence were evaluated at 0, 7, 14, 21, and 30 days. Results showed that sweet cherries were sensitive to both ethylene and 1-MCP treatments. Continuous ethylene exposure reduced abscisic acid accumulation, resulting in higher weight and firmness loss. Moreover, ethylene application decreased titratable acidity through storage, indicating an effect on sweet cherry senescence. No significant differences among treatments were found for soluble solids content and individual sugars. Conversely, 1-MCP preserved firmness during the first 7 days of storage, while reduced the incidence of physiological disorders at the end of storage life. Furthermore, 1-MCP delayed the accumulation of cyanidin-3-O-glucoside for 7 days compared to control and ethylene treated cherries. Taken together these results highlight the potential use of 1-MCP to extend the postharevst life of early season sweet cherry fruit

Influence of chitosan coating and storage temperatures on postharvest quality of guava

The effect of chitosan coating on postharvest quality of guava cv. Allahabad Safeda fruits stored at room temperature, 12° and 8°C was investigated. The fruits were either treated with chitosan (1 and 2%), acetic acid 1% or untreated and various quality attributes were studied at the end of storage period. Among the different treatments and temperatures, the chitosan 1% treated fruits stored at 12°C had shown higher firmness, TSS, titratable acidity and maintained greenness with a slow increase in yellow colour by the end of storage life. Also, the total antioxidant capacity, total phenols and total flavonoids of these fruits were well maintained by the time they are full ripe. Chitosan 1% and storage temperature of 12°C can be used for extending the storage life of guava upto 21 days with least deterioration in postharvest quality.

In-package atmospheric pressure cold plasma treatment of cherry tomatoes

Cold plasma is increasingly under research for decontamination of foods, especially fresh fruits and vegetables. The effect of cold plasma on food quality, however, remains under researched. This study investigates the effects of cold plasma generated within a sealed package from a dielectric barrier discharge on the physical quality parameters and respiration rates of cherry tomatoes. Respiration rates and weight loss were monitored continuously, while other parameters are reported at the end of storage period. Differences among weight loss, pH and firmness for control and treated cherry tomatoes were insignificant towards the end of storage life. Changes in respiration rates and colour of tomatoes were recorded as a function of treatment, which were not drastic. The results implicate that cold plasma could be employed as a means for decontamination of cherry tomatoes while retaining product quality.

Sensory, chemical and microbiological assessment of farm‐raised European sea bass (Dicentrarchus labrax) stored in melting ice

Farm raised European sea bass (Dicentrarchus labrax) were stored in melting ice for a period up to 22 days from the time of harvest, and sensory, chemical, and microbiological assessments were made at intervals. The storage life of the ungutted fish, determined by sensory evaluation of the cooked flesh, was 19 days. Of the chemical tests, only k1 value provided a useful means of monitoring early storage change. Trimethylamine, total volatile bases and pH showed practically no change during the first half of the edible storage life of the fish. Changes in free fatty acid (FFA) content and thiobarbituric acid (TBA) value could not be used to determine loss of acceptability or end of storage life. Sulphide producing bacteria constituted a very low proportion of the total aerobic flora, suggesting that the common sulphide producer Shewanella putrefaciens was not a major spoiler of sea bass in this trial.

A note on the microbiology of retail packs of prepared salad vegetables.

Retail packs of mixed, prepared salad vegetables from two different manufacturers were stored at 7 degrees C until the end of storage-life (sell-by date plus 1 d), when the microbial flora was examined. The quality of the salads was acceptable at the end of storage life. The oxygen concentrations in packs were lower, and the carbon dioxide concentrations were higher, than those in air. High numbers of bacteria were present, with Pseudomonas spp. and Enterobacter agglomerans predominating in packs of both salads, together with lactic acid bacteria in one of the salads. Significant numbers of pectolytic bacteria including Pseudomonas spp. and Erwinia carotovora were detected. Despite the presence of high numbers of coliform bacteria, Escherichia coli was not detected in batches of one salad, and was detected in relatively low numbers in batches of the other. Yersinia spp., predominantly environmental strains of Yersinia enterocolitica, were isolated by enrichment from all samples tested; Staphylococcus aureus and enterococci were not detected.

Effect of Cultivation and Nitrogen Levels on Storage Quality, Yield and Color Grade of Starking ‘Red Delicious’ Apple Grown Under Grass Sod1

Abstract ‘Starking Red Delicious’ trees 15 years old on seedling rootstocks were fertilized with 5 levels of N as ammonium nitrate from 0.165 to 3.0 lb. per tree applied in a narrow band from 1961 to 1966 and cultivated at a shallow depth with a rotavator each year in March and May, March alone, or not at all. Evaluation of fruit quality at harvest time showed that there was no significant effect of N level or cultivation treatments on fruit color. Pressure test was reduced by the higher N treatments but soluble solids concentration was highest at the medium N applications. Titratable acidity was reduced by the higher N treatments but cultivation treatments had no effect. Flesh color of the fruit was the most sensitive of several tests made, higher N and more cultivation causing greener flesh. In tests at the end of storage life, pressure test and titratable acidity were still reduced by the higher N treatments. There was little effect on soluble solids, per cent rots or storage scald. Again, cultivation treatments had no effect. There was very little difference in yield among the N treatments except at the lowest levels of 0.5 and 0.165 lb. This effect was most marked with no cultivation. The N content of the leaves was increased by the N treatments from approximately 2.1% at the lowest level to approximately 2.4% at the highest level. There was no effect on terminal length or trunk circumference. It was shown that grass sod with or without moderate cultivation could largely override the effect of a very wide range of N levels. There was a deleterious effect only at very low N levels combined with no cultivation.