Mário Roberto Maróstica

Chia (Salvia hispanica L.) enhances HSP, PGC-1α expressions and improves glucose tolerance in diet-induced obese rats

OBJECTIVE The aim of this study was to investigate the effects of chia seed and chia oil on heat shock protein (HSP) and related parameters in diet-induced obese rats. METHODS Animals were divided in six groups: control, high-fat and high-fructose diet (HFF), and HFF with chia seed or chia oil in short (6-wk) and long (12-wk) treatments. Plasma indicators of glucose tolerance and liver damage, skeletal muscle expression of antioxidant enzymes, and proteins controlling oxidative energy metabolism were determined. The limit of significance was set at P < 0.05. RESULTS The HFF diet induced glucose intolerance, insulin resistance, oxidative stress, and altered parameters related to obesity complications. The consumption of chia seed or chia oil did not reduce body weight gain or abdominal fat accumulation. However, chia seed and chia oil in both treatments improved glucose and insulin tolerance. Chia oil in both treatments induced expression of HSP70 and HSP25 in skeletal muscle. Short treatment with chia seed increased expression of HSP70, but not HSP25. Chia oil in both treatments restored superoxide dismutase and glutathione peroxidase expression. Extended treatment with chia seed and short treatment with chia oil restored peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression. CONCLUSION Chia oil restored the antioxidant system and induced the expression of a higher number of proteins than chia seed. The present study demonstrated new properties and molecular mechanisms associated with the beneficial effects of chia seed and chia oil consumption in diet-induced obese rats.

Antioxidant potential of dietary chia seed and oil (Salvia hispanica L.) in diet-induced obese rats

This study aimed to investigate the effects of dietary chia seed and oil on plasma and liver oxidative status in diet-induced obese rats. Thirty-six Wistar rats were divided in six groups (6 animals each): control group was fed the American Institute of Nutrition (AIN)-93M diet; HFF group was fed a high-fat and high-fructose (HFF) diet; chia seed short (6-weeks) and long (12-weeks) treatments received an HFF diet with chia seed; chia oil short (6-weeks) and long (12-weeks) treatments received an HFF diet with chia oil. Plasma and hepatic biomarkers of lipid peroxidation, endogenous enzymatic and non-enzymatic antioxidant systems and antioxidant capacity were determined. HFF diet induced weight gain, oxidative stress and lipid peroxidation in plasma and liver of animals. Compared to HFF group chia seed and chia oil (12 and 6weeks) intake increased plasma reduced thiol (GSH) levels, plasma catalase (CAT) and glutathione peroxidase (GPx) activities. In the liver glutathione reductase (GRd) activity was enhanced, while CAT and GPx activities did not change. There were no differences in plasma and liver superoxide dismutase activity among chia diets and HFF group. Chia (seed and oil) intake did not modify liver lipid peroxidation, but was able to reduce plasma thiobarbituric acid reactive substances (TBARS) and 8-isoprostane levels increased by HFF group. Plasma and hepatic antioxidant capacity values were increased in chia seed and oil groups about 35% and 47%, respectively, compared to HFF group. Chia groups presented similar antioxidant potential, regardless of treatment time. Dietary chia seed and oil reduced oxidative stress in vivo, since it improved antioxidant status and reduced lipid peroxidation in diet-induced obese rats.

Some Nutritional, Technological and Environmental Advances in the Use of Enzymes in Meat Products

The growing consumer demand for healthier products has stimulated the development of nutritionally enhanced meat products. However, this can result in undesirable sensory consequences to the product, such as texture alterations in low-salt and low-phosphate meat foods. Additionally, in the meat industry, economical aspects have stimulated researchers to use all the animal parts to maximize yields of marketable products. This paper aimed to show some advances in the use of enzymes in meat processing, particularly the application of the proteolytic enzymes transglutaminase and phytases, associated with nutritional, technological, and environmental improvements.

Volatile constituents of jabuticaba (Myrciaria jaboticaba (Vell.) O. Berg) fruits

Volatile flavor compounds of jabuticaba fruits (Myrciaria jaboticaba) were isolated using continuous liquid-liquid extraction and analyzed by various gas chromatographic techniques. Preparative gas chromatography was used to concentrate a fraction rich in potent flavor compounds. A total of 45 compounds were identified for the first time with 23 components imparting a sensory impression. Among the identified compounds, terpenes, organic acids and alcohols were found to be the major volatile components. Terpenes in particular contributed to the flavor of jabuticaba fruits. Application of aroma extract dilution analysis showed that β-pinene (woody-green), δ-cadinene (medicine), 2-phenylethanol (honey, flowery), and linalool (flowery) were the most potent odorants of jabuticaba fruits.

Tropical Fruit Flavour

The characteristic exotic flavour of fruits from the tropics is one of the most attractive attributes to consumers. Nowadays, food industries are looking at how to use these volatiles to produce amazing new products that can accommodate this new demand. The following sections report some of the relevant research data on volatiles of some important tropical fruits.

Are skeletally mature female rats a suitable model to study osteoporosis

OBJECTIVE To analyze if female Wistar rats at 56 weeks of age are a suitable model to study osteoporosis. MATERIALS AND METHODS Female rats with 6 and 36 weeks of age (n = 8 per group) were kept over a 20-week period and fed a diet for mature rodents complete in terms of Ca, phosphorous, and vitamin D. Excised femurs were measured for bone mass using dual-energy x-ray absorptiometry, morphometry, and biomechanical properties. The following serum markers of bone metabolism were analyzed: parathyroid hormone (PTH), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor Κappa B ligand (RANKL), C-terminal peptides of type I collagen (CTX-I), total calcium, and alkaline phosphatase (ALP) activity. RESULTS Rats at 56 weeks of age showed important bone metabolism differences when compared with the younger group, such as, highest diaphysis energy to failure, lowest levels of OC, CTX-I, and ALP, and elevated PTH, even with adequate dietary Ca. CONCLUSION Rats at 26-week-old rats may be too young to study age-related bone loss, whereas the 56-week-old rats may be good models to represent the early stages of age-related changes in bone metabolism.