Quality characteristics of a model biscuit containing processed mango (Mangifera indica) kernel flour

Mango (Mangifera indica) kernel was processed to flour and incorporated at 50% level of wheat flour substitution into biscuit (PMKWB) preparation. PMKWB was comparatively analysed with a commercial whole wheat biscuit (BRSCB) for several storage characteristics at 31 +/- 2degreesC and rate of peroxidation at 14, 31 and 58 +/- 2degreesC. Results showed that both biscuits had similar composition except in fat content. PMKWB was slightly more acidic than BRSCB due to the associated polyphenolic matter in the processed kernel flour used. BRSCB had more but negligible microbial load than PMKWB. On a 9-point hedonic scale, both biscuits were scored between 6.0 and 8.5 for attributes assessed though BRSCB scores were statistically higher (p < 0.05) than those of PMKWB. Both biscuits exhibited sigmoid-shaped Moisture adsorption isotherms with calculated monolayer moisture values of 4.0-4.5% (dry basis) using Brunauer-Emmett-Teller (BET) equation, and upper stability limits of 8.5-8.7% using the Henderson equation (rel. humidity, ca 52%). Both mathematical models fitted the biscuit isotherms well (rel. deviation, 3.0 to 4.5%). Peroxide values on the 90th day were 13, 21 and 56 meq/kg of PMKWB sample at 31, 14 and 58degreesC respectively. It was concluded that hygienically and commercially produced PMKWB would be shelf-stable for 3 months at temperatures not exceeding 31degreesC.