The effect of chitosan coating (1.0 and 1.5% w/v) in controlling decay of strawberries at 13°C was investigated as compared to a fungicide, iprodione (Rovralm). Chitosan coating significantly reduced decay of berries (PsO.05) compared to the control. There was no significant difference between chitosan and fungicide treatments up to 21 days storage. Thereafter, Rovrala-treated berries decayed at a higher rate than chitosan-coated berries. Chitosan-coated berries stored at 4°C were firmer, higher in titratable acidity, and synthesized anthocyanin at a slower rate than Rovrala-treated or nontreated berries. Chitosan coating decreased respiration rate of the berries with a greater effect at higher concentration.

No abstract

The effect of chitosan coating (1.0 and 1.5% w/v) on the storability of bell pepper and cucumber fruits stored at 13 and 20C (RH 85%) was determined by monitoring the weight loss, respiration and quality: Chitosan coating markedly reduced the weight loss in both bell pepper and cucumber at both temperatures. Increasing the concentration of chitosan from 1.0 to 1.5% (w/v) resulted in a significantly greater weight retention in both fruits. In addition, coating cucumber and bell pepper with chitosan reduced the respiration rate, loss of color, wilting and fungal infection. the mechanism by which chitosan coating delayed senescence in bell pepper and cucumber is most likely due to its ability to alleviate water stress.

No abstract

Milk permeate was separated at various temperatures by means of a hollow fibre ultrafiltration unit coupled to a stainless steel heat exchanger. Milk samples conditioned at 4 °C were heated to 20, 40, 60, 80, 85 or 90 °C prior to ultrafiltration. Ca, P, Mg, Na, K and citrate concentrations were measured in the permeate samples. Ca and P contents of the permeate decreased as the temperature increased. The pH was measured after cooling the permeate to room temperature. Smaller losses of Mg and citrate were also observed with increase in temperature. Na and K levels were not affected. A two-step time-concentration relationship was apparent for the species under study. An initial sharp decrease in concentration occurred in the first minute of holding time and was followed by a slower reaction. The possible occurrence of a two-step mechanism in the heat-induced salt balance changes is discussed. Dicalcium phosphate precipitation is believed to be coupled with tricalcium citrate precipitation upon heating.