Afshan Mumtaz Hamdani

Effect of guar gum conjugation on functional, antioxidant and antimicrobial activity of egg white lysozyme

This study was undertaken to analyze the effect of conjugation of egg-white lysozyme with guar gum. Lysozyme is an antimicrobial polypeptide that can be used for food preservation. Its antibacterial activity is limited to gram positive bacteria. Conjugation with polysaccharides like guar gum may broaden its activity against gram negatives. Conjugate was developed through Maillard reaction. Assays carried out included sugar estimation, SDS-PAGE, GPC, color, FT-IR, DSC, thermal stability, solubility, emulsifying, foaming and antioxidant activity. In addition, antimicrobial activity of the conjugate was determined against two gram positive (Staphyllococcus aureus and Enterococcus) and two gram negative pathogens (E. coli and Salmonella). Results showed higher functional properties of lysozyme-guar gum conjugate. The antioxidant properties increased from 2.02-35.80% (Inhibition of DPPH) and 1.65-4.93AAE/g (reducing power) upon guar gum conjugation. Conjugate significantly inhibited gram negative bacteria and the antibacterial activity also increased significantly against gram positive pathogens.

Physico-chemical, rheological and antioxidant properties of sweet chestnut (Castanea sativa Mill.) as affected by pan and microwave roasting

Graphical abstract

Effect of extrusion on the physicochemical and antioxidant properties of value added snacks from whole wheat (Triticum aestivum L.) flour

Nutritional quality of snacks prepared from cereals can be improved by the addition of crude lycopene (CL), tomato powder (TP) and saffron extracts (SE) which are known for their high photochemical content. The study was undertaken to prepare extruded snacks from whole wheat flour enriched with CL, TP and SE. Effect of extrusion on physicochemical, antioxidant and sensory properties of snacks was also investigated. Hardness of snacks containing CL and TP was higher than the control. Pasting properties of the formulations were significantly (p < 0.05) reduced upon addition of CL and TP. Total phenolic content (TPC) of the formulations with added TP increased significantly (p < 0.05). Antioxidant properties of snacks enhanced after enrichment. Extrusion significantly (p < 0.05) reduced the TPC, DPPH scavenging activity and pasting properties of snacks while, reducing power and inhibition of lipid peroxidation increased. Storage period lowered the hardness and antioxidant properties of snacks.

Effect of sonication and γ-irradiation on the properties of pea ( Pisum sativum ) and vetch ( Vicia villosa ) starches: A comparative study

In present study, the physicochemical, functional and pasting properties of starch obtained from commercially used pea were compared with vetch, an underutilized pulse variety. Starch from each cultivar was subjected to sonication (33kHz for 45min) and a dual treatment in which sonication was followed by irradiation (5kGy). Apparent amylose content of the starch from two varieties varied significantly (p>0.05) from 31.08-27.58g/100g. Sonication and dual treatment decreased the amylose content of starches. Syneresis varied more or less insignificantly (p<0.05) upon sonication. However, upon dual treatment, syneresis decreased significantly (p>0.05) from 47.82-35.22g/100g (pea) and 46.36-26.98g/100g (vetch) during the storage period of 120h. A combined effect of sonication and irradiation treatment significantly (p>0.05) changed the functional properties and pasting characteristics of starches. The samples that received the sonication treatment alone varied non-significantly from native pea and vetch starch in their physicochemical, functional and pasting properties.