Monitoring of compositional changes during berry ripening in grape seed extracts of cv. Sangiovese (Vitis vinifera L.).

BACKGROUND: Seed oil and flours have been attracting the interest of researchers and industry, since they contain various bioactive components. We monitored the effects of ripening on lipids, monomeric flavan-3-ols, proanthocyanidins and tocols concentration in seed extracts from organically cultivated cv. Sangiovese vines. RESULTS: Linoleic acid was the most abundant fatty acid, followed by oleic, palmitic and stearic acids. The tocols detected were α-tocopherol, α-tocotrienol and γ-tocotrienol. The proanthocyanidins degree of polymerisation ranged from dimers to dodecamers; moreover, monomeric flavan-3-ols and polymeric proanthocyanidins were detected. Total flavan-3-ols (monomers, oligomers and polymers) concentration in grape seeds decreased during ripening. CONCLUSIONS: Fatty acids reached the highest level in post-veraison. The concentration of these compounds varied considerably during ripening. Capric acid has been found for the first time in grape seeds. α-Tocopherol and γ-tocotrienol decreased during ripening, while α-tocotrienol increased. The HPLC analysis with fluorimetric detection, conducted for the first time on cv. Sangiovese, revealed that the concentration of flavan-3-ols monomers, oligomeric proanthocyanidins and polymers greatly changed during ripening. These results suggest that the timing of bunch harvest plays a crucial role in the valorisation of grape seed flour. © 2016 Society of Chemical Industry.

Counteraction of oxidative damage by pomegranate juice: influence of the cultivar.

BACKGROUND: Pomegranate (Punica granatum) has gained widespread popularity as a potential functional food due to its high phenolics content. Although in different studies pomegranate juice has been shown to exert anti-atherogenic, anti-inflammatory and antioxidant effects, the cultivar-related differences in phenolics content and antioxidant activity must be carefully taken into account when evaluating the health effects. The first aim of this study was to rank the juices of 15 different varieties of pomegranate according to their total phenolic content and antioxidant capacity. Then three juices were selected, better characterised and added to HepG2 cells as a supplement to evaluate the protective effect against induced oxidative stress. RESULTS: The cultivars Wonderful, Hicaz and G2 were chosen according to the ranking and the corresponding juices used at two different concentrations as a supplement to HepG2 cells. Overall, all juices were able to protect cells from oxidative damage, but differences that could be related to the different phenolics content and pattern were detected among the three juices. CONCLUSION: Our results show the advantage of screening cultivars prior to efficacy studies. This approach can be useful for food companies that focus on the development of food that has added nutritional and health value.

Bioactive lipids in the butter production chain from Parmigiano Reggiano cheese area.

BACKGROUND: Bovine milk contains hundreds of diverse components, including proteins, peptides, amino acids, lipids, lactose, vitamins and minerals. Specifically, the lipid composition is influenced by different variables such as breed, feed and technological process. In this study the fatty acid and phospholipid compositions of different samples of butter and its by-products from the Parmigiano Reggiano cheese area, produced by industrial and traditional churning processes, were determined. RESULTS: The fatty acid composition of samples manufactured by the traditional method showed higher levels of monounsaturated and polyunsaturated fatty acids compared with industrial samples. In particular, the contents of n-3 fatty acids and conjugated linoleic acids were higher in samples produced by the traditional method than in samples produced industrially. Sample phospholipid composition also varied between the two technological processes. Phosphatidylethanolamine was the major phospholipid in cream, butter and buttermilk samples obtained by the industrial process as well as in cream and buttermilk samples from the traditional process, while phosphatidylcholine was the major phospholipid in traditionally produced butter. This result may be explained by the different churning processes causing different types of membrane disruption. Generally, samples produced traditionally had higher contents of total phospholipids; in particular, butter produced by the traditional method had a total phospholipid content 33% higher than that of industrially produced butter. CONCLUSION: The samples studied represent the two types of products present in the Parmigiano Reggiano cheese area, where the industrial churning process is widespread compared with the traditional processing of Reggiana cow's milk. This is because Reggiana cow's milk production is lower than that of other breeds and the traditional churning process is time-consuming and economically disadvantageous. However, its products have been demonstrated to contain more bioactive lipids compared with products obtained from other breeds and by the industrial process.

Cholesterol and lipid oxidation in raw and pan-fried minced beef stored under aerobic packaging.

BACKGROUND: The type of packaging atmosphere has been reported as a technological factor that consistently affects the quality of lipid fraction in meat. Oxidation of cholesterol and lipids was evaluated before and after pan frying in commercial refrigerated minced beef stored under aerobic atmosphere for 1 and 8 days. RESULTS: In raw beef, cholesterol and lipid oxidation developed at a slow rate. Cholesterol oxidation products (COPs) did not significantly vary (approximately 8 microg COPs g(-1) of fat) over 8 days, while in the same period thiobarbituric acid reactive substances (TBARS) less than doubled (from 0.7 to 1.2 malondialdehyde equivalents kg(-1) of muscle). Pan frying did not influence the oxidative degree in the fresh product but consistently catalyzed cholesterol oxidation in stored beef. A significant increase was assessed in beef at the end of storage: from 8.6 to 30.0 microg COPs g(-1) of fat in raw and cooked beef, respectively. CONCLUSION: Aerobic packaging did not appear as a pro-oxidant factor in fresh minced beef with a good oxidative quality during a short period of refrigerated storage.