Effect of Hydrothermal and Non Thermal Treatments on Nutritional and Functional Properties of Pearl Millet Grain and Flour
C. J. Gnananethri *
Department of Food and Nutrition, Post Graduate and Research Centre, PJTS Agricultural University, Rajendranagar, Hyderabad-500030, Telangana, India.
Afifa Jahan
Department of Food and Nutrition, College of Community Science, Saifabad, Hyderabad-500004, Telangana, India.
Aparna Kuna
MFPI - Quality Control Laboratory, Department of Food and Nutrition, PJTSAU, EEI, Hyderabad, Telangana, India.
M V Nagesh Kumar
Maize Research Centre - ARI, Department of Genetics and Plant Breeding, PJTSAU, Rajendra nagar, Hyderabad, Telangana, India.
*Author to whom correspondence should be addressed.
Abstract
Aim: To investigate the effect of hydrothermal and non-thermal treatments on functional and nutritional properties of pearl millet grain and flour. Storage of produced grains and flour is one of the most crucial parts. Therefore, the development of innovative methods is required for the storage of millets, particularly pearl millet. This study concentrated on appropriate shelf life improving methods to raise the quality of its preservation. Consequently, to extend the pearl millet's shelf life, hydrothermal treatments as parboiling and non-thermal treatments like cold plasma and gamma radiation were used.
Study Design: Experimental design.
Methodology: Pearl millet (Pennisetum glaucum) PBH1625 variety (whole grain, dehulled grain and dehulled flour) was subjected to hydrothermal (parboiling) and non-thermal treatments (cold plasma and gamma radiation). Subsequently the samples were packed in low density polyethylene (LDPE) pouches and metalized polypropylene (MPP) stored for 90 days and analyzed for functional parameters viz. water absorption capacity, oil absorption capacity, foaming capacity and emulsifying capacity. Nutritional properties like moisture, fat, ash, protein and crude fiber.
Results: It was found that moisture content increases in all the control and treated samples among both type of packaging and the lowest was observed in whole grain exposed to gamma radiation at 0.75 kGy (10.263-12.223%) packed in MPP. The lowest Fat content ranges was observed in gamma radiated (0.75 kGy) whole grain (5.153-5.304%) packed in MPP. Highest ash content was seen in the gamma radiated (1.0 kGy) whole grain (2.004-2.017%) packed in LDPE. Similarly, highest protein content was noticed in gamma radiated (0.75 kGy) whole grain range (13.187-13.213%) packed in MPP. Crude fiber content drastically reduced in treated samples than control samples and highest was seen in the gamma radiated (0.75 kGy) whole grain (2.571-2.645%) packed in LDPE. During storage there was no significant increase in fat, ash, protein and crude fiber contents. The highest WAC was noticed in parboiled dehulled grain (1.322-1.511 g/g) packed in LDPE. Highest FC was seen in parboiled whole grain (14.790-14.903%) packed in LDPE. The highest EC was observed in the cold plasma treated (25kv for 10 mins) whole grain (45.720-45.916%) packed in LDPE. The highest OAC was noticed in the cold plasma treated (30kv for 10 mins) whole grain (1.377-1.446 g/g) packed in LDPE.
Keywords: Parboiling method, cold plasma treatment, gamma radiation, low density polyethylene (LDPE), metalized polypropylene (MPP)