Wheat germ stabilization by infrared radiation

GILI, RENATO; PALAVECINO, PABLO; MARÍA CECILIA PENCI; MARCELA L. MARTÍNEZ; PABLO D. RIBOTTA

JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE

ASSOC FOOD SCIENT TECHN INDIA

Año: 2017 vol. 54 p. 71 - 81

0022-1155

Wheat germ has an important enzymatic activity, being lipases the enzymes which cause the highestimpact in the reduction of shelf life. The objective of this study was to evaluate the effects of infraredradiation on wheat germ stabilization in an attempt to extend the shelf life. The effects of treatment time,gap (sample distance to IR emitters) and infrared radiation intensity on wheat germ were analyzed throughresponse surface methodology. Final moisture content, final temperature, color of germ and germ oilquality parameters: free fatty acid content changes and total tocopherol content were the responsesevaluated using a Box-Behnken design. A combination of an infrared radiation intensity of 4800 W/m2, a3 min treatment and 0.2 m emitter-sample distance were the best processing condition to stabilize thewheat germ without significantly reduction of the tocopherol content. A confirmatory experiment wasconducted with these optimal conditions, and the heat-treated and raw germ samples were stored for90 days at room temperature in three layer packages to protect them against light and oxygen. The oilquality parameters indicated that the raw germ had a shelf-life of about 15 days, with the heat-treatedwheat germ maintaining its quality for at least 90 days under these stored conditions.