Structure and stability of W1/O/W2 emulsions as influenced by WPC and NaCl in inner aqueous phase.

Effect of WPC and NaCl in internal aqueous phase (W1) of W1/O/W2 type double emulsions was studied. Pre-emulsion and final emulsion were prepared using microfluidizer and Ultra-Turrax high shear mixer, respectively. The emulsions prepared using salt exhibited uniform droplet size distribution and structural integrity. WPC at 6% and NaCl at 2 or 4% levels demonstrated better sedimentation stability (> 99%) and encapsulation stability (> 95%) during preparation and storage of double emulsions. Samples without added NaCl showed poor emulsion stability and structural integrity. Higher level of WPC i.e. 8% resulted in poor stability and encapsulation efficiency of double emulsions at all salt levels. Combined use of optimum levels of WPC and NaCl along with processing interventions resulted in stable double emulsions even after storage at room temperature for 10 days. This study highlights the fact that structural integrity of internal aqueous phase (W1) depends upon presence of osmotic agent i.e. salt and stabilising proteins i.e. WPC.

Effect of clove bud and curry leaf essential oils on the anti-oxidative and anti-microbial activity of burfi, a milk-based confection.

With scientific advancement in the field of food science and technology, there has been an increased availability of innovative ingredients that can be utilized towards value addition, quality enhancement, natural preservation, shelf life enhancement and adding novelty to traditional Indian dairy products. Here a scientific attempt has been made to increase the anti-oxidative and anti-microbial potential of burfi, a popular confection of Indian sub-continent with low shelf life using herbal essential oils (EOs) (natural preservative, antioxidant and antimicrobial) such as curry leaf (CRYF) (0.05-0.15 ppm) and clove bud (CLVB) (0.15-0.25 ppm) EO. Samples were subjected to physico-chemical, sensory, anti-oxidant and microbiological analysis and the results revealed that increasing the herbal EOs levels in burfi led to increase in anti-microbial and anti-oxidative attributes but simultaneously decreased the sensory attributes. Physico-chemical attributes remained unaffected upon EOs incorporation. Principal component analysis revealed 81.5% relation between the burfi samples and its quality attributes (DPPH activity, ABTS activity, total phenolic content, sensory attributes, standard plate count, yeast and mould count, moisture content, water activity, lightness, L* value, redness, a* value and yellowness, b* value). Herbal EOs i.e. CRYF@0.10 ppm and CLVB@0.20 ppm on khoa basis were found optimum for incorporation into burfi for enhancing storage stability without compromising the sensory acceptability.

Evaluation of quality changes in nutritionally enriched extruded snacks during storage.

The aim of this study was to evaluate changes in the physical, chemical and sensory properties of a low fat-high protein, fiber enriched extruded snack. It was packed in metalized polypropylene/polyethylene (PP/PE) laminate pouches, under modified atmosphere packaging (MAP) with nitrogen flushing and without nitrogen flushing (control) and stored for a period of 22 weeks at 37 ± 1 °C and 80% RH. MAP had significant impact on the moisture content, aw, TBA value, Hunter L* value and crispiness of the extruded snacks during storage. The moisture content of the snack significantly increased from 3.68 to 5.16% in control and from 3.66 to 4.31% in MAP. The oxidative rancidity in terms of TBA value of control sample increased from 0.02 to 0.07 while the product packaged under MAP, the value increased to 0.056. The sensory scores for flavour, color and appearance, texture and overall acceptability (OA) of the product significantly decreased during storage, but the product stored under MAP had better flavor (6.51) and OA scores (6.85) compared to control (5.58 and 6.04, respectively), after 22 weeks of storage. Thus, MAP tended to retard the storage induced changes and it could suitably be utilized for the delivery of low fat-high protein, fiber enriched extruded snacks to the consumer, while keeping the sensorial acceptance of the product for 5 months.

Aloe vera (Aloe barbadensis Miller) supplemented probiotic lassi prevents Shigella infiltration from epithelial barrier into systemic blood flow in mice model.

The aim of present work was to investigate preventive role of orally administered Aloe vera supplemented probiotic lassi (APL) on Shigella dysenteriae infection in mice. At the end of experimental period (2, 5 and 7 days of challenging), different organs such as spleen, liver, small intestine, large intestine, and peritoneal fluid were collected and assessed for Shigella colonization. Secretary IgA was estimated in intestinal fluid. Blood was collected in heparinized tubes for various haematological studies. Oral administration of APL showed a significant (p < 0.05) reduction in the Shigella counts (log cfu/mL) in all organs as compared to other treatment groups at different intervals after post feeding. Similarly, secretary IgA antibody levels (µg/mL) in intestinal fluid were significantly (p < 0.05) increased in case of APL fed mice. Further, feeding of APL also demonstrated a positive effect on different haematological parameters viz. Hb (gm %), RBC and WBC count. The results indicated the immunoprotective effects of APL against Shigella dysenteriae induced infection in mice.

Process optimisation for preparation of caseinophosphopeptides from buffalo milk casein and their characterisation.

Caseinophosphopeptides (CPPs) are multifunctional bioactive peptides containing phosphorylated seryl residues in their sequence. In the present study, method for the production of CPPs from buffalo milk casein was optimised and characterised for their sequence, calcium solubilising and calcium binding activities. Response surface methodology was used to optimise the conditions for hydrolysis of buffalo casein by trypsin to obtain maximum yield of CPPs. The optimum hydrolysis conditions were as follows: hydrolysis pH 7.5, temperature 37 °C, hydrolysis time 7.0 h. Under these conditions, the experimental yield obtained was 10.04±0.24%, which is slightly lower than value predicted by the model. These CPPs were able to solubilise 1.03±0.08 mg la/mg CPPs in presence of excess phosphate and bind 0.935 mg of Ca/mg of CPPs. Eight phosphopeptides, i.e., α(s1)-CN f (37-58) 2P; α(s1)-CN f (37-58) 3P; α(s1)-CN f (35-58) 2P; α(s1)-CN f (35-58) 3P; α(s2)-CN f (2-21) 4P; α(s2)-CN f (138-149) 1P; ß-CN f (2-28) 4P and ß-CN f (33-48) 1P were identified by LC-MS/MS which contained motif for binding of divalent minerals. The sequences of these CPPs differed from that of derived from bovine casein.