Utility of heating pattern with variable air temperature in drying; effects on drying time, energy consumption, and product quality.

Drying with variable air temperature is a technique to decrease the drying time, preserve quality and maintain the nutritional components of products. The aim of this study was to find the effect of different heating patterns with variable air temperatures on the drying time, energy consumption and the quality of garlic as well as investigate the critical times to change the air temperature. The constant air temperatures were 50, 60, and 70 °C, and the variable air temperature included three patterns of 60 °C → 50 °C (I), 70 °C→50 °C (II), and 70 °C (30 minutes) →50 °C (III). Despite preventing garlic slices' color changes in the constant air temperature of 50 °C, the antioxidant contents of the samples reduced significantly (45%), and the drying time was 136 minutes. At the air temperature of 70 °C, the color changes peaked, and the drying time was 65 minutes. The best drying condition was observed among the variable air temperature by pattern III. The drying time and loss of antioxidants were 24% and 45% lower than the one in the constant air temperature of 50 °C; besides, the effective moisture diffusivity was 24% higher. The color changes of these samples were lower compared to other patterns and the final product had acceptable quality and was produced in an optimal time.

Administration of grape (Vitis vinifera) seed extract to rainbow trout (Oncorhynchus mykiss) modulates growth performance, some biochemical parameters, and antioxidant-relevant gene expression.

Grape seed, as a main source of polyphenols, has many nutritional and medicinal properties in humans. In the current study, the effects of dietary ethanolic grape seed extract (GSE) on the growth performance, antioxidant activity, and some biochemical parameters in rainbow trout were investigated. Ninety fish (initial weight 78.47 g) were randomly distributed among nine cement tanks (1.8 m × 0.22 m × 0.35 m) with 10 fish per tank. Three experimental diets containing either 0, 10, or 50 g kg-1 GSE were prepared and each diet was randomly assigned to three tanks of fish for 60 days. Results showed that feeding GSE enhanced some growth parameters including the specific growth rate and condition factor in comparison with the control group. Among different serum metabolites, the glucose levels in treatment groups significantly decreased compared to the control group. The total product of lipid peroxidation indicated as malondialdehyde significantly decreased in both the GSE-added treatment groups. The gene expression related to the antioxidant enzymes, catalase, glutathione peroxidase 1, and glutathione S-transferase A, were upregulated in the intestine of fish that received a low dose of GSE. The results of the current study suggest that GSE, especially at 10 g kg-1, diet had the potential to improve (1) specific growth rate and condition factor, (2) biochemical parameters including glucose and lipid peroxidation product, and (3) upregulated the expression of antioxidant genes including catalase, glutathione peroxidase 1, and glutathione S-transferase A in rainbow trout.

Effects of salicylic acid on Aspergillus flavus infection and aflatoxin B1 accumulation in pistachio (Pistacia vera L.) fruit.

BACKGROUND: One of the most important saprophytic infections in fresh pistachio fruits after harvesting is Aspergillus flavus colonization, which significantly reduces fruit quality. Salicylic acid plays a crucial role in plant tissues and has a suppression effect on some fungi. RESULTS: The inhibitory effect of salicylic acid on the growth of A. flavus was assessed in vitro and in vivo. For this purpose, seven concentrations (0, 1, 3, 5, 7, 9 and 11 mmol L(-1)) of salicylic acid were used in both experiments. Also, aflatoxin B1 contents of the samples were analysed using immunoaffinity chromatography. The results obtained from in vitro experiments showed that salicylic acid significantly reduced Aspergillus growth at all concentrations, and at 9 mmol L(-1) growth was completely suppressed. In vivo evaluation showed relatively high levels of inhibition, though the intact treated fruits as compared with the injured treated fruits demonstrated higher inhibitory effects. CONCLUSION: Regarding the inhibitory effects of salicylic acid on the control of A. flavus contamination, its application on pistachio fruits after harvesting could be a promising approach to control the fungus infection and reduce aflatoxin production in treated fruits.