Impact of microwave irradiation on chemically modified talipot starches: A characterization study on heterogeneous dual modifications.

In this study, the effect of chemical modifications such as oxidation, esterification and crosslinking was investigated alone and in combination with microwave irradiation on a non-conventional starch with 76% starch yield acquired from the trunk of matured talipot palm. The single- and dual-modifications imparted significant changes in the morphological, crystalline, pasting and rheological properties and digestibility of talipot starch. Characteristic peaks were observed in single- and dual-oxidized, esterified and crosslinked starches indicating their respective functional groups. All modifications significantly decreased (p ≤ 0.05) the relative crystallinity (RC) of talipot starches except for crosslinking, and the least RC (11.33%) was observed in microwave irradiated esterified starch. Microwave irradiation prior to chemical modifications showed a significant impact in the swelling and solubility of talipot starches. The decreased setback viscosity and increased light transmittance in single- and dual-microwave irradiated talipot starches showed their lowered retrogradation tendency, suitable for frozen foods. The resistant starch (RS) content was majorly improved in all heterogeneously dual modified talipot starches by incorporating more functional groups owed to structural and crystalline destruction in starch granules upon microwave irradiation. The highest RS content (45.02%) was observed in microwave irradiated esterified uncooked talipot starch.

Maximal oxygen uptake is lower for a healthy Indian population compared to white populations.

PURPOSE: Presently used prediction equations for maximal oxygen uptake are mostly derived from studies of western populations. However, the interracial differences are quite large when prediction equations for the Western-white population are applied to Asian-Indians. The present study was aimed at the initial development of a prediction equation for the healthy sedentary Indian participants using symptom limited graded incremental exercise testing and to compare the new regression equation to other published data. METHODS: Participants were staff and caregivers of patients from different states of India. All participants completed a maximal graded exercise test on a motorized treadmill at Christian Medical College, Vellore, Tamil Nadu to determine maximal oxygen uptake (VO(2)max). RESULTS: Predictive equations for both men and women were obtained from multiple linear regression analysis and significant correlations were found for weight and height. The correlation coefficients of the new regression equations with measured VO(2)max of study population were R(2) = .511 for men and R(2) = .656 for women. These were compared with other published equations with differences ranging from 7% to 50% for men and 10% to 36% for women. CONCLUSIONS: The present study derived a prediction equation for VO(2)max applicable to the Asian-Indian population. The predicted maximal oxygen uptake of the study population using the new equation is significantly lower than the white population. The new equation may facilitate more meaningful interpretation of the test data in this population and possibly a wider use.