Determination of variability in rancidity profile of select commercial Pearl millet varieties/hybrids

Pearl millet (Pennisetum glaucum), one of the world’s hardiest cereal crop can grow under harsh climatic conditions. It is grown in the drylands, mostly by smallholder farmers and forms part of the staple diet for millions of resource-poor people in the drylands. However, flour prepared from this climate-change-ready crop has a low shelf-life, attributed to the nature of the fat. Thus, pearl millet has to be ground fresh before use adding to the drudgery of the consumers, especially women. Commercialization of pearl millet flour, which is also in demand in the urban market due to its health benefitting properties, has been constrained due to this rancidity problem. Thus, a study was initiated to evaluate the suitability of popular Indian commercial varieties/hybrids for obtaining shelf-stable flour. Two parameters indicating rancidity namely acid value (indicates enzymatic rancidity) and peroxide value (indicates oxidative rancidity) were monitored during the study. Flour from each variety was stored under three storage conditions – Refrigerated (4°C), room temperature (25°C) and accelerated (35°C, 70%RH) and their acid and peroxide values measured at regular intervals. The study clearly established the existence of diversity in the rancidity profile among the select varieties/hybrids of pearl millet studied. Pearl millet varieties/hybrids that are least susceptible to rancidity can be promoted for use in production of self-stable pearl millet flour in conjunction with appropriate processing and packaging technologies.