Effects of two different water sources used for irrigation on the soil geochemical properties and the quality of the Lohan guava (Psidium guajava L. Lohan).

The effect of two different water sources (treated waste water and lake water) used for irrigation on the soil geochemical properties and the fruit quality parameters of the Lohan guava were studied. The fruits' physical attributes, physicochemical attributes, nutritional attributes, mineral content as well as consumers' acceptance were evaluated. The properties of the different water sources and their effect, on both the soil and the quality of the fruits, were evaluated. Analysis of the irrigation water revealed that treated waste water was of acceptable quality with reference to irrigation water quality guidelines, while the lake water used for irrigation fell short in several aspects. The different water sources used for irrigation in the farms affected the soil geochemical properties significantly. The quality of guavas harvested from the farms that were irrigated with different water sources was significantly different. Irrigation water qualities were observed to have positive effects on the quality of the fruits and consumers' acceptance as observed from the results of quality analysis and the consumers' acceptance test.

Effect of postharvest ultraviolet-C treatment on the proteome changes in fresh cut mango (Mangifera indica L. cv. Chokanan).

BACKGROUND: Postharvest treatments of fruits using techniques such as ultraviolet-C have been linked with maintenance of the fruit quality as well as shelf-life extension. However, the effects of this treatment on the quality of fruits on a proteomic level remain unclear. This study was conducted in order to understand the response of mango fruit to postharvest UV-C irradiation. RESULTS: Approximately 380 reproducible spots were detected following two-dimensional gel electrophoresis. Through gel analysis, 24 spots were observed to be differentially expressed in UV-C treated fruits and 20 were successfully identified via LCMS/MS. Postharvest UV-C treatment resulted in degradative effects on these identified proteins of which 40% were related to stress response, 45% to energy and metabolism and 15% to ripening and senescence. In addition, quality and shelf-life analysis of control and irradiated mangoes was evaluated. UV-C was found to be successful in retention of quality and extension of shelf-life up to 15 days. Furthermore, UV-C was also successful in increasing antioxidants (total flavonoid, reducing power and ABTS scavenging activity) in mangoes. CONCLUSION: This study provides an overview of the effects of UV-C treatment on the quality of mango on a proteomic level as well as the potential of this treatment in shelf-life extension of fresh-cut fruits. © 2015 Society of Chemical Industry.

Effects of ultraviolet light (UV-C) and heat treatment on the quality of fresh-cut Chokanan mango and Josephine pineapple.

The effects of ultraviolet (UV-C) and medium heat (70 °C) treatments on the quality of fresh-cut Chokanan mango and Josephine pineapple were investigated. Quality attributes included physicochemical properties (pH, titratable acidity, and total soluble solids), ascorbic acid content (vitamin C), antioxidant activity, as well as microbial inactivation. Consumers' acceptance was also investigated through sensory evaluation of the attributes (appearance, texture, aroma and taste). Furthermore, shelf-life study of samples stored at 4 ± 1 °C was conducted for 15 d. The fresh-cut fruits were exposed to UV-C for 0, 15, 30, and 60 min while heat treatments were carried out at 70 °C for 0, 5, 10 and 20 min. Both UV-C and medium heat treatments resulted in no significant changes to the physicochemical attributes of both fruits. The ascorbic acid content of UV-C treated fruits was unaffected; however, medium heat treatment resulted in deterioration of ascorbic acids in both fruits. The antioxidants were enhanced with UV-C treatment which could prove invaluable to consumers. Heat treatments on the other hand resulted in decreased antioxidant activities. Microbial count in both fruits was significantly reduced by both treatments. The shelf life of the fresh-cut fruits were also successfully extended to a maximum of 15 d following treatments. As for consumers' acceptance, UV-C treated fruits were the most accepted as compared to their heat-treated counterparts. The results obtained through this study support the use of UV-C treatment for better retention of quality, effective microbial inactivation and enhancement of health promoting compounds for the benefit of consumers.

Effects of sonication and ultraviolet-C treatment as a hurdle concept on quality attributes of Chokanan mango (Mangifera indica L.) juice.

The growing demand for fresh-like food products has encouraged the development of hurdle technology of non-thermal processing. In this study, freshly squeezed Chokanan mango juice was treated by paired combinations of sonication (for 15 and 30 min at 25 ℃, 40 kHz frequency) and UV-C treatment (for 15 and 30 min at 25 ℃). Selected physicochemical properties, antioxidant activities, microbial inactivation and other quality parameters of combined treated juice were compared to conventional thermal treatment (at 90 ℃ for 60 s). After thermal and combined treatment, no significant changes occurred in physicochemical properties. A significant increase in extractability of carotenoids (15%), polyphenols (37%), flavonoids (35%) and enhancement in antioxidant capacity was observed after combined treatment. Thermal and combined treatment exhibited significant reduction in microbial load. Results obtained support the use of sonication and UV-C in a hurdle technology to improve the quality of Chokanan mango juice along with safety standards.

Effects of thermal treatment and sonication on quality attributes of Chokanan mango (Mangifera indica L.) juice.

Ultrasonic treatment is an emerging food processing technology that has growing interest among health-conscious consumers. Freshly squeezed Chokanan mango juice was thermally treated (at 90 °C for 30 and 60s) and sonicated (for 15, 30 and 60 min at 25 °C, 40 kHz frequency, 130 W) to compare the effect on microbial inactivation, physicochemical properties, antioxidant activities and other quality parameters. After sonication and thermal treatment, no significant changes occurred in pH, total soluble solids and titratable acidity. Sonication for 15 and 30 min showed significant improvement in selected quality parameters except color and ascorbic acid content, when compared to freshly squeezed juice (control). A significant increase in extractability of carotenoids (4-9%) and polyphenols (30-35%) was observed for juice subjected to ultrasonic treatment for 15 and 30 min, when compared to the control. In addition, enhancement of radical scavenging activity and reducing power was observed in all sonicated juice samples regardless of treatment time. Thermal and ultrasonic treatment exhibited significant reduction in microbial count of the juice. The results obtained support the use of sonication to improve the quality of Chokanan mango juice along with safety standard as an alternative to thermal treatment.