Preservative potential of Tinospora cordifolia, a novel natural ingredient for improved lipid oxidative stability and storage quality of chevon sausages

Effect of Teucrium trifidum powder on some meat quality attributes of chevon under refrigerated storage

We investigated the effect of T. trifidum on the shelf-life and quality of chevon kept for eight days at 4 ± 1 °C in polyethylene pouches. Different powder levels of T. trifidum (0.5 %, 1.0 %, and 2.0 % w/w) and 0.02 % w/w butylated hydroxytoluene (BHT) were used to treat the chevon samples. The T. trifidum and BHT treated chevon was compared to untreated chevon (control). Colour, ferric reducing antioxidant power (FRAP), lactic acid bacteria (LAB) counts, oxidative stability, pH and total viable counts (TVC) were all measured while the samples were in storage. Treatment demonstrated a significant (P < 0.05) influence on pH with chevon preserved with T. trifidum powder (2 %), having a lower pH than the chevon preserved with BHT and the control. The colour of chevon (lightness, redness and yellowness) was shown to differ (P < 0.05) across treatments. The redness (a∗) and yellowness (b∗) reduced as the refrigeration period lengthened (P < 0.05).

In contrast, the lightness (L∗) of chevon intensified as the storage period lengthened (P < 0.05). The TBARS considerably reduced (P < 0.05) in samples subjected to T. trifidum powder and BHT, with respect to the untreated sample. There was an increase in the FRAP activity as the amount of T. trifidum powder (P < 0.05) was increased. The FRAP values were shown to be inversely related to the TBARS values, implying that the addition of T. trifidum powder could slow lipid oxidation. In comparison with the control, T. trifidum powder inhibited bacterial growth during storage as measured by a significant reduction in TVC and LAB counts (P < 0.05). It is concluded that, T. trifidum powder has potent antioxidant and antimicrobial activity in refrigerated ground chevon thus can be potentially used to preserve the quality of refrigerator stored ground chevon.

Effect of processing technologies on the digestibility of egg proteins

Egg and egg products are a rich source of highly bioavailable animal proteins. Several processing technologies can affect the structural and functional properties of these proteins differently and can influence their fate inside the gastrointestinal tract. The present review examines some of the processing technologies for improving egg protein digestibility and discusses how different processing conditions affect the digestibility of egg proteins under gastrointestinal digestion environments. To provide up-to-date information, most of the studies included in this review have been published in the last 5 years on different aspects of egg protein digestibility. Digestibility of egg proteins can be improved by employing some processing technologies that are able to improve the susceptibility of egg proteins to gastrointestinal proteases. Processing technologies, such as pulsed electric field, high-pressure, and ultrasound, can induce conformational and microstructural changes that lead to unfolding of the polypeptides and expose active sites for further interactions. These changes can enhance the accessibility of digestive proteases to cleavage sites. Some of these technologies may inactivate some egg proteins that are enzyme inhibitors, such as trypsin inhibitors. The underlying mechanisms of how different technologies mediate the egg protein digestibility have been discussed in detail. The proteolysis patterns and digestibility of the processed egg proteins are not always predictable and depends on the processing conditions. Empirical input is required to tailor the optimization of processing conditions for favorable effects on protein digestibility.

Thermal processing implications on the digestibility of meat, fish and seafood proteins

Thermal processing is an inevitable part of the processing and preparation of meat and meat products for human consumption. However, thermal processing techniques, both commercial and domestic, induce modifications in muscle proteins which can have implications for their digestibility. The nutritive value of muscle proteins is closely related to their digestibility in the gastrointestinal tract and is determined by the end products that it presents in the assimilable form (amino acids and small peptides) for the absorption. The present review examines how different thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect the digestibility of muscle proteins in the gastrointestinal tract. By altering the functional and structural properties of muscle proteins, thermal processing has the potential to influence the digestibility negatively or positively, depending on the processing conditions. Thermal processes such as sous-vide can induce favourable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility whereas processes such as stewing and roasting can induce unfavourable changes, such as protein aggregation, severe oxidation, cross linking or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. The review examines how the underlying mechanisms of different processing conditions can be translated into higher or lower protein digestibility in detail. This review expands the current understanding of muscle protein digestion and generates knowledge that will be indispensable for optimizing the digestibility of thermally processed muscle foods for maximum nutritional benefits and optimal meal planning.