Effect of Osmotic and Pickling Pretreatments on Nutritional Quality and Acceptance of Traditional Fermented Oyster Mushrooms

The study was conducted to evaluate the pretreatment effects of ascorbate and osmotic solution on oven dried and pickled mushrooms. Significant differences in nutritional composition and sensory quality were observed between the pickled and dried samples of mushrooms. Pickling obtained in high moisture content, crude fibre, crude fat, crude protein, soluble solid and ash content, however, the content of carbohydrates and dry matter were lower than oven drying. Both osmotic and ascorbate pretreatments significantly affected the composition. As result, ascorbate concentration increased the protein, ash and fat contents of mushroom samples. In contrary to ascorbate pretreatment, osmotic solution pretreated mushrooms resulted in highest rehydration capacity. The sensory evaluation results of the pickled mushrooms products had more acceptances and acquired good colour, flavour and overall acceptability than that of oven dried products. Ascorbate treatments combined with pickling are advantageous in terms of mushroom quality as compared to oven drying methods and osmotic pretreatments. Unlike osmotic pretreatments, the mushrooms that were pretreated in ascorbate were maintained their nutritional compositions, acidity and physical quality. Keywords: Ascorbate, osmotic, pretreatments, mushroom, pickling, oven drying, nutritional quality, consumer acceptabilit

A review on integrated agro-technology of vegetables

The aim of this review was threefold: First, to explore the effect of different preharvest treatments on postharvest quality of fruits and vegetables. Second, the principles of biological, chemical and biochemical changes in fruits and vegetables during development, maturation, ripening and storage were reviewed. Third postharvest handling and factors affecting quality of fruits and vegetables were examined. These include disinfecting, packaging and storage temperature. Pre- and postharvest treatments were found to have an effect on postharvest quality of fruit and vegetables, suggesting that postharvest quality of produce subjected to preharvest treatments should be assessed from a quality improvement, maintenance and consumer safety point of view. Literature recommends an integratedagro-technology approach towards improving quality at harvest and maintenance of qualities of fruits and vegetables.Keywords: Agro-technology, vegetables, fruits, preharvest treatments, ripening, postharvest handling, storag

Integrated agrotechnology with preharvest ComCat® treatment, modified atmosphere packaging and forced ventilation evaporative cooling of carrots

Preharvest ComCat® treatment of carrots was investigated for storage characteristics of treated vegetables in forced ventilation evaporative cooling. The forced ventilation evaporative cooling system was designed such that the temperature could be reduced by 8.4 - 13.4°C below ambient temperature, while maintaining a relative humidity up to 91%. Storage in this EC increased shelf lives of carrots to 24 days, compared to 4 days when stored at ambient conditions. ComCat® treatment of carrots significantly (P 0.05) affected pH, total sugar content and the population of moulds and yeasts during storage at evaporative cooling. Modified atmosphere packaging significantly (P 0.001) reduced physiological weight loss, moisture and juice content of carrots stored inside evaporative cooling. Modified atmosphere packaging coupled with evaporative cooling reduced the rate of sugar utilization for metabolic activities, compared to unpackaged carrots stored at ambient conditions. The populations of aerobic bacteria and fungi were significantly (P 0.001) affected by modified atmosphere packaging coupled with evaporative cooling temperature. Disinfecting with chlorinated water helped additionally to limit microbial growth during evaporative cooling storage

DETERMINATION OF PERFORMANCE AND ASSOCIATED ECONOMIC COSTS OF INDIRECT AIR-COOLING COMBINED WITH EVAPORATIVE COOLING FOR STORAGE OF TOMATOES IN SOUTH AFRICA

Knowledge of the cost of a storage structure for fruits and vegetables is paramount as a decision tool when farmers consider the return on investment. The performance and economic analysis associated with using a solar-powered indirect air-cooling (IAC) combined with evaporative cooling (EC) storage structure for storage of green harvested tomatoes was investigated. This study investigated the effect of IAC+EC system and period of storage on the quality of tomatoes over a 28 day storage period. The construction, maintenance and operation costs of an IAC+EC system were also studied. Various quality attributes of tomatoes were investigated by monitoring the storage of green harvested tomato fruit over 28 days under both IAC+EC system and ambient conditions with data collated every seven days. Tomatoes stored under IAC+EC conditions had significantly (P<0.01) higher firmness, lower total soluble solids content, lower physiological weight loss and higher average percentage marketability than those under ambient conditions over the storage period. The tomatoes stored in the cold storage conditions were 28.1% more resistant to puncture; had 7,3% less total soluble solids content, had three times less physiological weight loss, than those stored under ambient conditions over the same period. The h° and L* values decreased progressively over the period of storage from 84% at day 0 to 48.31% and 50.43% at day28 under ambient and IAC+EC conditions, respectively. Tomatoes stored under IAC+EC conditions had a higher average percentage marketability (72.4%) than those under ambient conditions (40.9%) over the storage period. The cost of constructing a 53-m3 IAC+EC system integrated with a solar photovoltaic system was US$8,680. The economic analysis that the payback period of the cooling system was less than two years. The results demonstrate that the IAC+EC system could be recommended for small-scale farmers in sub-Saharan Africa to maintain a better quality of produce if government and other funding agencies come on board

DETERMINATION OF PERFORMANCE AND ASSOCIATED ECONOMIC COSTS OF INDIRECT AIR-COOLING COMBINED WITH EVAPORATIVE COOLING FOR STORAGE OF TOMATOES IN SOUTH AFRICA

Knowledge of the cost of a storage structure for fruits and vegetables is paramount as a decision tool when farmers consider the return on investment. The performance and economic analysis associated with using a solar-powered indirect air-cooling (IAC) combined with evaporative cooling (EC) storage structure for storage of green harvested tomatoes was investigated. This study investigated the effect of IAC+EC system and period of storage on the quality of tomatoes over a 28 day storage period. The construction, maintenance and operation costs of an IAC+EC system were also studied. Various quality attributes of tomatoes were investigated by monitoring the storage of green harvested tomato fruit over 28 days under both IAC+EC system and ambient conditions with data collated every seven days. Tomatoes stored under IAC+EC conditions had significantly (P<0.01) higher firmness, lower total soluble solids content, lower physiological weight loss and higher average percentage marketability than those under ambient conditions over the storage period. The tomatoes stored in the cold storage conditions were 28.1% more resistant to puncture; had 7,3% less total soluble solids content, had three times less physiological weight loss, than those stored under ambient conditions over the same period. The h° and L* values decreased progressively over the period of storage from 84% at day 0 to 48.31% and 50.43% at day28 under ambient and IAC+EC conditions, respectively. Tomatoes stored under IAC+EC conditions had a higher average percentage marketability (72.4%) than those under ambient conditions (40.9%) over the storage period. The cost of constructing a 53-m3 IAC+EC system integrated with a solar photovoltaic system was US$8,680. The economic analysis that the payback period of the cooling system was less than two years. The results demonstrate that the IAC+EC system could be recommended for small-scale farmers in sub-Saharan Africa to maintain a better quality of produce if government and other funding agencies come on board

Integrated agrotechnology with preharvest ComCat® treatment, modified atmosphere packaging and forced ventilation evaporative cooling of tomatoes

An evaporative cooler (EC) unit, which allowed an average drop of 11.5°C in temperature and a rise of 43.93% in relative humidity relative to environmental conditions was used to store tomatoes. Thequality of tomatoes stored in this cooler were maintained better with more than 70% shelf life extension compared to tomatoes stored at ambient conditions. Preharvest ComCat® treated tomatoes containedlower TSS, reducing sugars and total sugars at harvest, and showed better keeping quality in terms of PWL, juice content, TSS and sugars, compared to untreated controls. No distinct effect of ComCat®treatment on microbial populations was found. Disinfecting with chlorinated water controlled total aerobic bacteria, moulds and yeasts during storage in the EC. MAP and EC temperatures helped tocontrol weight loss, improve juice content, total aerobic bacteria, moulds and yeasts and resulted in lower pH of stored tomatoes. Microperforated MAP film prevented condensation inside packages andresulted in better marketability when combined with EC. The benefits from the combined effect of pre- and postharvest treatment on tomatoes include: reduction of PWL and loss of fruit juice, better keeping quality in terms of TSS, pH, non-reducing sugar content, total sugar content, microbiological quality, and marketability

Review on postharvest technology of banana fruit

The aim of this review is in threefold: First, to explore the effect of different preharvest treatments on postharvest quality of fruits and vegetables. Second, the principles of biological, chemical and biochemical changes in banana during development, maturation, ripening and storage were reviewed. Third, postharvest handling and factors affecting quality of banana were examined. These include disinfecting, packaging and storage temperature. Pre- and postharvest treatments were found to have an effect on postharvest quality of banana, suggesting that postharvest quality of produce subjected to preharvest treatments should be assessed from a quality improvement, maintenance and consumer safety point of view. Literature recommends an integrated agro-technology approach towards improving quality at harvest and maintenance of qualities of banana.Keywords: Banana, fruit, postharvest handling, packaging, storageAfrican Journal of Biotechnology Vol. 12(7), pp. 635-64