Functional properties of protein hydrolysates from fresh water mussel Lamellidens marginalis (Lam.)

Bioactive peptides from dietary proteins are used as nutraceuticals. An objective of the present investigation is to produce enzymatically hydrolysed bioactive peptides from the freshwater mussel Lamellidens marginalis (Lam.), an unconventional low cost protein source, using commercial food grade proteases such as alcalase® 2.4 L and pepsin. Functional characteristics which include protein solubility at different pH, emulsifying, foaming, fat absorption, water holding capacities and antioxidant activity of protein hydrolysates and isolates were evaluated for their utilisation in different food products. The mussel protein hydrolysates showed improved functional properties as evident from emulsifying and foaming capacities. Protein Solubility increased significantly at pH 7 in both hydrolysates of different time fractions. The antioxidative property as well as the free radical scavenging activity and ferric reducing the antioxidant power of ultrafiltered (<3 kDa) hydrolysates at different concentrations demonstrated that pepsin has maximum efficacy. Biochemical analyses reveal that hydrolysates can be commercialized as a source of potential antioxidative nutraceuticals. Administration of such bioactive peptides in optimum doses may help to mitigate health ailments. Moreover, the therapeutic potential of bioactive peptides from L. marginalis has not yet been explored so much for translational research/applications. This scenario has prompted us to evaluate the potential of bioactive peptides from Lamellidens marginalis for nutraceutical therapy.

Biochemical assessment of extract from Oxalis corniculata L.: Its role in food preservation, antimicrobial and antioxidative paradigms using in situ and in vitro models

Food poisoning, often due to microbial contamination and improper storage practice, is a matter of concern. Plants and plant based products are gaining interest in processed food in food industry as an alternative to synthetic antimicrobials. In this context, here, we analysed flavonoid rich methanolic extract from the creeping woodsorrel, Oxalis corniculata L. leaf for its biochemical assessments along with its bioactivity against some common pathogenic bacteria. The bioactivity of the extract as evaluated in both in vitro and in situ methods, verified that the Oxalis corniculata leafextract exert reduces power, hydroxyl radical scavenging activity, inhibition in liposome peroxidation, and DPPH free radical quenching activity. The extract also inhibited the formation of peroxide during subsequent storage in the oil-emulsion system as well as in heated oil. The greater reducing activity of the extract prevented hydroxyl radical induced pUC18 DNA strand breaks and there by retain its original conformation. The extract also prevented the oxidative damage of goat liver cells during Fenton reaction. In vitro antimicrobial experiments implied that extract has inhibitory effect against Staphylococcus aureus, Escherichia coli, Salmonella Typhi, S. Typhiimurium and Vibrio cholera. E. coli showed the highest and V. cholera the lowest sensitivities against the extract. Moreover, the extract can be utilized for preservation of fish meat as it prevented the growth of food poisoning bacteria S. aureus during storage at 10°C. HPLC chromatogram detected the predominance of three active principal components, i.e. flavonoids in the following order: rutin>p-hydroxybenzoic acid>ferulic acid.

Protective effect of secondary plant metabolites from Ipomoea aquatica Forsk. against carbofuran induced damages.

Plausible interactions between food contaminants and natural constituents in vivo and protective effect of polyphenols present in I. aquatica against carbofuran toxicity in Charles Foster rats were evaluated. Determinations based on antioxidant enzyme activities showed significant alterations in glutathione, glutathione peroxidase, superoxide dismutase and catalase in tissues (liver and brain) and plasma of pesticide treated group while polyphenolic extracts from I. aquatica (IAE) attenuated their activities when given alongwith carbofuran. IAE decreased enhanced lipid peroxidation levels in plasma and erythrocyte membrane and cholesterol levels in brain and plasma. IAE also minimized histopathological degenerative changes produced by carbofuran. While single cell gel electrophoresis showed that secondary metabolites in leafy vegetables produced a combinatorial effect with pesticide at cellular level, DNA fragmentation level in bone marrow cells showed a decline in the IAE treated rats. Food safety adversely affected by various chemical contaminants can be retained by plant polyphenols and secondary plant constituents that can be found together in bolus. Therefore, the present study gives an insight into the protective role of naturally found polyphenols against pesticide toxicity.