Effects of industrial heat treatments on bovine milk oxylipins and conventional markers of lipid oxidation.

The effects of industrial heat treatments of raw bovine milk subjected to Batch Pasteurization (BP), High Temperature Short Time (HTST) and Ultra High Temperature (UHT) on the formation of primary (hydroperoxide content and oxylipins) and secondary lipid oxidation products (thiobarbituric acid reactive species -TBARS) were evaluated. Total fatty acid content, percent of free fatty acids (FFA), and total antioxidant capacity (TAC) were also measured. Except for a 30% reduction in capric acid (C10:0) after UHT compared to BP, no significant differences in total fatty acid concentrations were detected amongst the heat treatments. Compared to raw bovine milk, no statistically significant effects of heat treatment were observed on percent FFA (0.29-0.31%), hydroperoxide concentration (0.0558-0.0624 mmol L-1), and TBARS values (13.4-18.9 µg MDA kg-1). HTST and UHT led to significant reductions (50-65%) in linoleic and alpha-linolenic acid oxidized metabolites compared with raw milk and batch pasteurized milk. Compared to raw milk (2943.7 µmol of TEAC L-1), TAC was significantly reduced by all heat treatments (2245 - 2393 µmol of TEAC L-1), although no statistically significant differences were observed amongst the treatments. The results demonstrate that heat processing reduces milk oxylipin content and antioxidant capacity and that oxylipin and TAC measurements provide a new sensitive approach to assess the impact of milk processing on lipid oxidation. The nutritional, shelf life and sensory implications of reduced oxylipins in HTST and UHT processed bovine milk merit further investigation.

Can lychee reducing the adipose tissue mass in rats?

ABSTRACT Lychee fruit has been studied owing to the presence of several bioactive compounds that can contribute to weight loss in obese individuals. However, the anti-obese potential of the fruit has not been explored yet. The aim of this study was to investigate the effect of different parts of lychee in reducing the adipose tissue mass of cafeteria diet-fed rats. Phenolic compounds and scavenging capacities were quantified. The food intake, apparent digestibility, weight of the body and liver, body mass, Lee Index, and the mass of epididymal and visceral adipose tissues were evaluated. The results were estimated by Tukey's Test at 5% probability. A higher amount of phenolic compounds and scavenging capacity were observed in the peel of lychee as compared to the other parts of the fruit. The hypercaloric diet with lychee flour resulted in a higher apparent digestibility. There was no difference between groups control (C), hypercaloric (H), hypercaloric with lychee flour - 50.00% peel and 50.00% seeds (H2F), and hypercaloric with lychee flour - 33.33% peel, 33.33% pulp and 33.34% seeds (H3F) with respect to body and liver weight, corporal mass, and Lee Index. The hypercaloric diet-fed group exhibited an increase in visceral and epididymal adipose tissue mass, whereas the group fed with hypercaloric diets and flour made from the peel and seed of lychee presented a lower visceral adipose tissue mass. In conclusion, the use of lychee flour was considered viable because it decreased visceral adipose tissue mass in rats.