Browsing by Author "Chian FM"

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    Alternative proteins vs animal proteins: The influence of structure and processing on their gastro-small intestinal digestion
    (Elsevier Ltd, 2022-04) Kaur L; Mao B; Beniwal AS; Abhilasha; Kaur R; Chian FM; Singh J
    Background: Digestibility, an indicator of protein bioavailability, is essentially a measure of the susceptibility of a protein towards proteolysis. Proteins with higher digestibility have been linked with better health outcomes. Animal proteins are generally considered to be of better nutritional value than plant proteins not only because they are a good source of essential amino acids but also due to their higher digestibility in the human gastro-intestinal tract. With the recent emergence of alternative food protein sources, which are now processed in a completely new way to design new foods or new versions of the conventional foods, it has become extremely important to understand their digestion characteristics. Scope and approach: This review discusses the factors that affect protein digestibility, including protein source, structure, type of processing, and modification, with a particular focus on the effects of non-protein components present in food matrix. Key findings and conclusions: To obtain the desired functionality, particularly for alternate proteins, numerous physical, chemical, and enzymatic methods for modification have been reported. These modifications may alter structural characteristics of proteins by inducing structural modifications such as protein unfolding, crosslinking, and aggregation. Depending upon the protein reactivity during processing, the susceptibility of proteins towards hydrolysis by digestive enzymes might change, affecting not only the overall protein digestibility but also the rates of release of polypeptides and amino acids. The faster rates of protein digestion have been linked with muscle anabolism, suggesting the need and importance of classifying the new, emerging and alternative protein sources according to their rates of digestion into rapidly (RDP), slowly digestible (SDP) and resistant (RP) proteins. More research needs to be focussed on converting, through processing, the undigestible or RP into RDP or SDP to achieve better health outcomes.
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    Endogenous Proteolytic Systems and Meat Tenderness: Influence of Post-Mortem Storage and Processing
    (Korean Society for Food Science of Animal Resources (KoSFA), 2021-07-01) Kaur L; Hui SX; Morton JD; Kaur R; Chian FM; Boland M
    Meat proteolytic systems play a crucial role in meat tenderisation. Understanding the effects of processing technologies and post-mortem storage conditions on these systems is important due to their crucial role in determining the quality characteristics of meat and meat products. It has recently been proposed that tenderisation occurs due to the synergistic action of numerous endogenous proteolytic systems. There is strong evidence suggesting the importance of μ-calpain during the initial post-mortem aging phase, while m-calpain may have a role during long-term aging. The caspase proteolytic system is also a candidate for cell degradation in the initial stages of conversion of muscle to meat. The role of cathepsins, which are found in the lysosomes, in post-mortem aging is controversial. Lysosomes need to be ruptured, through aging, or other forms of processing to release cathepsins into the cytosol for participation in proteolysis. A combination of optimum storage conditions along with suitable processing may accelerate protease activity within meat, which can potentially lead to improved meat tenderness. Processing technologies such as high pressure, ultrasound, and shockwave processing have been reported to disrupt muscle structure, which can facilitate proteolysis and potentially enhance the aging process. This paper reviews the recent literature on the impacts of processing technologies along with post-mortem storage conditions on the activities of endogenous proteases in meat. The information provided in the review may be helpful in selecting optimum post-mortem meat storage and processing conditions to achieve improved muscle tenderness within shorter aging and cooking times.
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    Protein and Lipid Digestibility of Pasture-Raised and Grain-Finished Beef: An In Vitro Comparison
    (MDPI (Basel, Switzerland), 2023-03-14) Kaur L; Elamurugan A; Chian FM; Zhu X; Boland M; Gagaoua M
    This study compared the digestibility of protein and fat components of pasture-raised and grain-finished beef using an in vitro oral-gastro-small intestinal digestion model. Two commonly consumed beef cuts, tenderloin (Psoas major) and striploin (Longissimus dorsi) were selected for this study. There were no substantial differences between the pasture-raised and grain-finished cuts of meat in terms of protein digestibility, as shown by the protein and peptide breakdown (observed through SDS-PAGE) and the degree of hydrolysis as measured by free amino nitrogen. Tenderloin, however, showed significantly (p < 0.05) higher overall protein digestibility than striploin. Both striploin and tenderloin digests from pasture-raised beef released significantly (p < 0.05) higher total amounts of free long-chain n-3 PUFAs and lower amounts of many free saturated fatty acids, notably palmitic and myristic acids, than those from grain-finished animals. The results suggest greater health benefits from consuming pasture-raised beef, particularly tenderloin.