Esterified unpopped foxnut (Euryale ferox) starch: molecular and rheological characterization

BACKGROUND

Acetylated-based starches are broadly used in the food industry as emulsifiers, and as thickening and film-forming agents. Better understanding of the structural and rheological parameters would facilitate the selection of optimal acetylated starches for particular applications. Nuclear magnetic resonance (¹ H-NMR), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) patterns, and rheological properties, including elasticity (G'), loss (G") moduli, complex viscosity (η*) and study shear stress (δ), were determined for acetylated fox nut starch (FNS) samples.

RESULTS

The degree of substitution (DS) varied significantly with increasing acetyl concentration from 2-6%. Nuclear magnetic resonance analysis of acetylated FNS showed an additional chemical shift at 2.08 ppm in comparison with native FNS, confirming the linking of the H or the -OCH3 group. The acetylated FNS starches showed better short-range ordering of molecules, as confirmed by FTIR. A significant increase in the functional and gelatinization properties with increasing acetyl concentration was observed. The power law parameters (n, K) and dynamic moduli (G' and G") increased with increasing acetyl concentration and presented shear thinning behavior. The gelatinization peak temperature and enthalpy decreased with increasing acetyl concentration.

CONCLUSION

The observed DS below 2.5 would mean safe food consumption and the significant alteration of functional and structural properties with varying acetyl content will extend the use of FNS in food and allied industries. © 2023 Society of Chemical Industry.

HLA antigen pattern of Kashmiri patients with rheumatic heart disease

The distribution of HLA class-I (A, B and C), and class II (DR and DQ) antigens was studied in 50 randomly selected Kashmiri Muslim patients with established rheumatic heart disease and compared with that of 50 controls of similar ethnicity. A significant increase in the frequency of HLA-DR4 (P < 0.005, RR 3.27) and a significant decrease in the frequency of HLA-B5 (P < 0.001, RR 0.19) were found in the patient group. Though HLA-DQ3 showed a significant increase (P < 0.005, RR 2.52) and HLA-DR7 a significant decrease (P < 0.05, RR 0.42) in the patient group, the corrected P value was not significant. The findings suggest that susceptibility to RHD in the studied population is HLA-related, with HLA-DR4 influencing its occurrence and HLA-B5 conferring protection against the same.

Lead exposure in papier mâché workers

Lead exposure was assessed in a random cohort of 70 male papier mâché workers and compared with 35 age and sex matched controls. Blood-lead levels in workers were significantly higher than in controls (Mean 68.07 +/- 44.64 ug/dl vs 25.52 +/- 16.56 ug/dl respectively; P < 0.001). Urinary lead was also higher in workers (128.53 +/- 52.61 ug/l) compared to controls (91.18 +/- 27.06, P < 0.001), but excretion of urinary coproporphyrin in the two groups was not significantly different (102.78 +/- 153.42 vs 70.03 +/- 27.06 ug/l, P > 0.05). Blood levels bore a significant correlation with age but did not bear any correlation with the duration of exposure. Various modes of exposure to lead included hand mixing of paints, skin application of the paint to match shades and making point of the brush using lips and the tongue.