Impact of quercetin conjugation using alkaline and free radical methods with tandem ultrasonication on the functional properties of camel whey and its hydrolysates.

The structural and functional properties of whey-quercetin and whey hydrolysate-quercetin conjugates synthesized using alkaline and free radical-mediated methods (AM and FRM) coupled with sonication were studied. FTIR showed new peaks at 3000-3500 cm-1 (N-H stretching regions) and the 1000-1100 cm-1 region with the conjugates. Conjugation increased the random coils and α-helix content while decreasing the ß-sheets and turns. It also increased the particle size and surface hydrophobicity which was significantly (p < 0.05) higher in AM than FRM conjugates. AM conjugates had higher radical scavenging activity but lower quercetin content than FRM conjugates. Overall, the functional properties of whey-quercetin conjugates were better than whey hydrolysate-quercetin conjugates. However, hydrolysate conjugates had significantly higher denaturation temperatures irrespective of the method of production. Sonication improved the radical scavenging activity and quercetin content of FRM conjugates while it decreased both for AM conjugates. This study suggested that whey-quercetin conjugates generally had better quality than whey hydrolysate conjugates and sonication tended to further improve these properties. This study highlights the potential for using camel whey or whey hydrolysate-quercetin conjugates to enhance the functional properties of food products in the food industry.

Exploring the impact of various cooking techniques on the physicochemical and quality characteristics of camel meat product.

OBJECTIVE: The objective of this study was to evaluate the effects of four different cooking techniques viz: boiling, grilling, microwave, and frying; on the physicochemical characteristics of camel meat. METHODS: Protein composition and their degradation as well as biochemical and textural changes of camel meat as influenced by cooking methods were investigated. RESULTS: The highest cooking loss (52.61%) was reported in microwaved samples while grilled samples showed the lowest cooking loss (44.98%). The microwaved samples showed the highest levels of lipid oxidation as measured by thiobarbituric acid reactive substances, while boiled samples showed the lowest levels (4.5 mg/kg). Protein solubility, total collagen, and soluble collagen content were highest in boiled samples. Boiled camel meat had lower hardness values compared to the other treated samples. Consequently, boiling was the more suitable cooking technique for producing camel meat with a reduced hardness value and lower lipid oxidation level. CONCLUSION: The camel meat industry and camel meat consumer can benefit from this research by improving their commercial viability and making consumers aware about the effects of cooking procedures on the quality of camel meat. The results of this study will be of significance to researchers and readers who are working on the processing and quality of camel meat.

A comparative investigation into novel cholesterol esterase and pancreatic lipase inhibitory peptides from cow and camel casein hydrolysates generated upon enzymatic hydrolysis and in-vitro digestion.

Cow (CwC) and camel casein (CaC) hydrolysates were generated using Alcalase™ (CwCA and CaCA) and Pronase-E (CwCP and CaCP) each for 3 and 6 h, and investigated for their potential to inhibit key lipid digesting enzymes i.e., pancreatic lipase (PL) and cholesteryl esterase (CE). Results revealed stronger PL and CE inhibition by CaC hydrolysates compared to CwC. Potent hydrolysates (CwCP-3 h and CaCA-6 h) upon simulated gastrointestinal digestion (SGID) showed significant improvement in inhibition of both PL and CE. However, both the SGID hydrolysates showed similar extent of PL and CE inhibition and were further sequenced for peptide identification. Peptides MMML, FDML, HLPGRG from CwC and AAGF, MSNYF, FLWPEYGAL from CaC hydrolysates were predicted to be most active PL inhibitory peptides. Peptide LP found in both CwC and CaC hydrolysates was predicted as active CE inhibitor. Thus, CwC and CaC could be potential source of peptides with promising CE and PL inhibitory properties.

Conjoint application of ultrasonication and redox pair mediated free radical method enhances the functional and bioactive properties of camel whey-quercetin conjugates.

Ultrasonication, redox-pair generated free radical method and their combination (Ultrasonication/redox-pair method) was used for production of camel whey-quercetin conjugates. FTIR and SDS-PAGE confirmed successful production of whey-quercetin conjugates using ultrasonication and ultrasonication/redox-pair method. FTIR suggested existence of covalent (appearance of new peak at 3399 cm-1) and non-covalent linkages (shifting of peak at 3271 cm-1, 1655 cm-1 (amide I), 1534 cm-1 and 1422 cm-1 (Amide II)) in the whey-quercetin conjugates. Moreover, SDS-PAGE of conjugates produced by ultrasonication as well redox-pair method indicated shifting of protein bands slightly towards high molecular weight due to increase in the mass of proteins due to the binding of polyphenols. All conjugates showed improved techno-functional and bioactive properties in comparison to whey proteins. Conjugates produced through ultrasonication showed smaller particle size, improved solubility, emulsifying and foaming properties while conjugates produced through ultrasonication/redox-pair method depicted superior antioxidant properties in comparison to whey. Furthermore, conjugated samples showed higher inhibition of enzymatic markers involved in diabetes and obesity with highest potential recorded in conjugates produced using ultrasonication. Therefore, ultrasonication can be successfully used individually as well as in combination with redox-pair for production of whey-quercetin conjugates with enhanced bioactive and techno-functional properties.

Whey protein-polyphenol conjugates and complexes: Production, characterization, and applications.

Whey proteins are widely used as functional ingredients in various food applications owing to their emulsifying, foaming, and gelling properties. However, their functional attributes are limited in some applications because of the dependence of their performance on pH, mineral levels, and temperature. Several approaches have been investigated to enhance the functional performance of whey proteins by interacting them with polyphenols via covalent bonds (conjugates) or non-covalent bonds (complexes). The interaction of the polyphenols to the whey proteins alters their molecular characteristics, techno-functional attributes, and biological properties. Analytical methods for characterizing the properties of whey protein-polyphenol complexes and conjugates are highlighted, and a variety of potential applications within the food industry are discussed, including as antioxidants, emulsifiers, and foaming agents. Finally, areas for future research are highlighted.

New insights into the cholesterol esterase- and lipase-inhibiting potential of bioactive peptides from camel whey hydrolysates: Identification, characterization, and molecular interaction.

Novel antihypercholesterolemic bioactive peptides (BAP) from peptic camel whey protein hydrolysates (CWPH) were generated at different time, temperature, and enzyme concentration (%). Hydrolysates showed higher pancreatic lipase- (PL; except 3 CWPH) and cholesterol esterase (CE)-inhibiting potential, as depicted by lower half-maximal inhibitory concentration values (IC50 values) compared with nonhydrolyzed camel whey proteins (CWP). Peptide sequencing and in silico data depicted that most BAP from CWPH could bind active site of PL, whereas as only 3 peptides could bind the active site of CE. Based on higher number of reactive residues in the BAP and greater number of substrate binding sites, FCCLGPVPP was identified as a potential CE-inhibitory peptide, and PAGNFLPPVAAAPVM, MLPLMLPFTMGY, and LRFPL were identified as PL inhibitors. Molecular docking of selected peptides showed hydrophilic and hydrophobic interactions between peptides and target enzymes. Thus, peptides derived from CWPH warrant further investigation as potential candidates for adjunct therapy for hypercholesterolemia.

Identification and characterization of novel α-amylase and α-glucosidase inhibitory peptides from camel whey proteins.

This study explores the inhibitory properties of camel whey protein hydrolysates (CWPH) toward α-amylase (AAM) and α-glucosidase (AG). A general full factorial design (3 × 3) was applied to study the effect of temperature (30, 37, and 45°C), time (120, 240, and 360 min), and enzyme (pepsin) concentration (E%; 0.5, 1, and 2%). The results showed that maximum degree of hydrolysis was obtained when hydrolysis was carried out at higher temperature (45°C; P < 0.05), compared with lower temperatures of 30 and 37°C. Electrophoretic pattern displays degradation of all protein bands upon hydrolysis by pepsin at various hydrolysis conditions applied. All the 27 CWPH generated showed significant AAM and AG inhibitory potential as indicated by their lower IC50 values (mg/mL) compared with intact whey proteins. In total 196 peptides were identified from selected hydrolysates and 15 potential peptides (PepSite score > 0.8; http://pepsite2.russelllab.org/) were explored via in silico approach. Novel peptides PAGNFLMNGLMHR, PAVACCLPPLPCHM, MLPLMLPFTMGY, and PAGNFLPPVAAAPVM were identified as potential inhibitors for both AAM and AG due to their high number of binding sites and highest binding probability toward the target enzymes. CCGM and MFE, as well as FCCLGPVPP were identified as AG and AAM inhibitory peptides, respectively. This is the first study that reports novel AG and AAM inhibitory peptides from camel whey proteins. The future direction for this research involves synthesis of these potential AG and AAM inhibitory peptides in a pure form and investigate their antidiabetic properties in the in vitro, as well as in vivo models. Thus, CWPH can be considered for potential applications in glycaemic regulation.

Effect of different ripening stages on walnut kernel quality: antioxidant activities, lipid characterization and antibacterial properties.

Packing tissue between and around the kernel halves just turning brown (PTB) is a phenological indicator of kernel ripening at harvest in walnuts. The effect of three ripening stages (Pre-PTB, PTB and Post-PTB) on kernel quality characteristics, mineral composition, lipid characterization, sensory analysis, antioxidant and antibacterial activity were investigated in fresh kernels of indigenous numbered walnut selection of Kashmir valley "SKAU-02". Proximate composition, physical properties and sensory analysis of walnut kernels showed better results for Pre-PTB and PTB while higher mineral content was seen for kernels at Post-PTB stage in comparison to other stages of ripening. Kernels showed significantly higher levels of Omega-3 PUFA (C18:3n3) and low n6/n3 ratio when harvested at Pre-PTB and PTB stages. The highest phenolic content and antioxidant activity was observed at the first stage of ripening and a steady decrease was observed at later stages. TBARS values increased as ripening advanced but did not show any significant difference in malonaldehyde formation during early ripening stages whereas it showed marked increase in walnut kernels at post-PTB stage. Walnut extracts inhibited growth of Gram-positive bacteria (B. cereus, B. subtilis, and S. aureus) with respective MICs of 1, 1 and 5 mg/mL and gram negative bacteria (E. coli, P. and K. pneumonia) with MIC of 100 mg/mL. Zone of inhibition obtained against all the bacterial strains from walnut kernel extracts increased with increase in the stage of ripening. It is concluded that Pre-PTB harvest stage with higher antioxidant activities, better fatty acid profile and consumer acceptability could be preferred harvesting stage for obtaining functionally superior walnut kernels.

Comparison of cheese and paneer whey for production of a functional pineapple beverage: Nutraceutical properties and Shelf life.

Whey, a dairy byproduct offers a challenging task in terms of its disposal. Two functional beverages were produced by blending pineapple juice with cheese whey (W1B) and paneer whey (W2B) at different concentrations (10 %, 20 % and 30 %). The beverages were compared for physico-chemical, microbial and nutraceutical properties over a period of 60 days. Whey addition significantly improved various physico-chemical parameters of the beverages. Higher protein content in W1B and a higher mineral content in W2B without any adverse effects on antioxidant activity was seen because of blending. Whey based beverages showed higher microbial content, sedimentation values and serum separation values than control at all levels of blending. Although, W1B showed highest protein and microbial count but W2B showed highest mineral content and improved shelf life due to significantly lower values of serum separation and sedimentation. It could be concluded that paneer whey based pineapple beverage enable byproduct utilization with excellent nutrition and nutraceutical quality.

Ultrasound treatment: effect on physicochemical, microbial and antioxidant properties of cherry (Prunus avium).

The cherry was treated with ultrasonic waves (33 kHz, 60 W) at different time intervals (10, 20, 30, 40, 60 min) and study was carried out to analyze the change in physico-chemical properties (TSS, pH, color, acidity and firmness), antioxidant potential and microbial load of the fruit during the storage period of 15 days at 4 °C. It was observed that ultrasound treatment (US) between 30 and 40 min showed better retention of color of the fruit during the storage period. The antioxidant assays (DPPH, ABTS and TPC) also increased significantly (P ≤ 0.05) up to 40 min, however the firmness of the fruit was affected and it showed a significant decrease beyond 20 min of US treatment. The sample with 40 min US treatment showed significantly less microbial load than other samples. The 20-40 min US treatment time (33 kHz, 60 W) was suggested for preservation of cherry during the storage at 4 °C.

Wheat-water chestnut flour blends: effect of baking on antioxidant properties of cookies.

Proximate composition, mineral content, functional, pasting and antioxidant properties of water chestnut flour (WCF) were compared with refined wheat flour. WCF showed higher phenolic (4.25 gGAE/1000 g), flavonoid (1.92 g QE/1000 g) and mineral content (K, Mg, Zn, Cu) than wheat flour. WCF showed greater retrogradation tendency but lower peak viscosity than wheat flour. Wheat flour - WCF blends and cookies were evaluated for water activity, physical & textural properties. Water activity of cookies decreased significantly (0.415-0.311) with increase in level of WCF in wheat flour. Total phenolic content, flavonoid content and antioxidant activity (DPPH• scavenging capacity, FRAP) of WCF - wheat flour blends as well as their cookies was also determined. Baking led to a greater increase in DPPH• scavenging capacity of WCF cookies (33.8%) than WF cookies (25%). Baking had a similar effect on FRAP value. Wheat flour cookies showed a decrease of 51%, and 62% while WCF cookies showed a decrease of 36%, and 34% in TPC and TFC values respectively. WCF cookies thus showed better retention of antioxidant activities suggesting greater stability of WC phenolics than wheat phenolics. Sensory analysis showed cookies made from water chestnut (100%) had fair acceptability due to their characteristic flavor. Thus, water chestnut flour serves both as a gluten free as well as antioxidant rich flour for production of cookies.

Characterization of cookies made from wheat flour blended with buckwheat flour and effect on antioxidant properties.

Buckwheat flour was incorporated into wheat flour at different levels (0, 20, 40, 60, 80, and 100 %) and the physicochemical, functional and antioxidant properties of the blended flour were studied. This study also investigated the effect of buckwheat on the retention of antioxidant properties of cookies during baking. The results showed significant variation in physicochemical and functional properties of the blended flour. The addition of buckwheat flour into wheat flour also increased the antioxidant properties of blended flour proportionally, but metal chelating properties decreased. The incorporation of buckwheat in wheat flour helped in better retention of antioxidant potential of cookies during baking process as buckwheat cookies (100 % buckwheat) showed greater percentage increase in antioxidant properties than control (100 % wheat). Quality characteristics of cookies such as hardness and spread ratio decreased, while as non-enzymatic browning (NEB) increased significantly with increase in the proportion of buckwheat flour in wheat flour. The Overall acceptability of cookies by sensory analysis was highest at 40 % level of blending. This study concluded that addition of buckwheat in wheat flour, may not only improve the physico-chemical and functional properties of the blended flour but may also enhance the nutraceutical potential of the product prepared from it.

Effect of green tea powder on thermal, rheological & functional properties of wheat flour and physical, nutraceutical & sensory analysis of cookies.

Green tea powder (GTP) was incorporated in wheat flour at different levels (1, 2 and 4 %) and its effect on quality parameters of flour and cookies were studied. Thermal analysis showed that addition of GTP did not increase the onset temperature, end temperature and enthalpy of flour significantly. However, the increase in GTP content retarded the retro gradation of the gelatinized wheat flour gel and decreased the water absorption capacity, Oil absorption capacity, water solubility index, Foam capacity and foam stability significantly. The L* and b* values of cookies decreased from 53.63 to 33.23 and 29.02 to 24.39 respectively, while as, a* value showed an increase from 3.61 to 5.23 indirect proportion to quantity added. The addition of GTP to wheat flour increased the DPPH (2,2-diphenyl-1-picrylhydrazyl) percent inhibition and reducing power of cookies. Further, it also increases the acceptability for color, aroma and taste; however it loosened its structural integrity and decreased the fracture force.