Influence of processing conditions on quality of Indian small grey donkey milk powder by spray drying.

The study was carried out to know the quality of small grey donkey milk powder by spray dryer. Donkey milk powder moisture, fat, protein, carbohydrate and ash were 4.12 (d.b), 5.97, 22.84, 4.64 and 62.43 (%). Donkey milk powder was produced at milk total solids of 20, 25 and 30% concentration at 160, 170 and 180 °C inlet air temperature using two fluid flow nozzle type atomizer of 0.84 mm diameter, pressure of 1.75 kg.cm-2, flow rate of 0.5 L.h-1, blower speed of 2100 rpm. L * , a * , b * and aw values decreased with increasing concentrated milk feed as well as inlet air temperature. Density decreased as increase of inlet air temperature and increased as increase milk concentration. Flowability was fair according to Hausner ratio (1.25) and Carr's index (20%) values. The heat utilization efficiency increased as increase of concentration and decreased as increase of inlet air temperature. Solubility decreased as increase of concentration and inlet air temperature. Dispersibility decreased as increase of inlet air temperature and increased as increase of concentration. Wetting time increased as increase of concentration and inlet air temperature. Structure of the donkey milk powder was spherical and minerals were abundant.

Physico-chemical composition, minerals, vitamins, amino acids, fatty acid profile and sensory evaluation of donkey milk from Indian small grey breed.

Composition, nutritional value and sensory characteristics of donkey milk of Indian small grey breed was analysed using AOAC and other standard methods. Fresh donkey milk had 90.63% (w.b.) moisture content, 0.76% fat, 1.96% protein, 6.30% lactose, 0.40% ash. Particle size of donkey milk was 355.00 d.nm. The UHPLC analysis ascertained that lysozyme content was more in donkey milk sample. The ICPMS confirmed that Ca, K, Mg, Na, vitamin C and E, glutamic acid, leucine, proline were the most abundant in donkey milk, but Fe, Zn, Vitamin A and B1, methionine shown lower amount. The GC analysis determined that butyric acid, lauric acid was more and lower amount of unsaturated fatty acids were observed in donkey milk sample. Finally, the TPC, yeast and mould count were acceptable and confirmed that donkey milk is microbiologically safe and sensory evaluation studies of donkey milk confirmed that the desired sensory attributes.

Shelf-life and colour change kinetics of Aloe vera gel powder under accelerated storage in three different packaging materials.

Aloe vera gel powder was produced through dehumidified air drying of Aloe vere gel at optimized conditions of temperature, relative humidity and air velocity of 64 °C, 18% and 0.8 m.s(-1), respectively. The powder was packed in three different packaging materials viz., laminated aluminum foil (AF), biaxially oriented polypropylene (BOPP) and polypropylene (PP). The shelf-life of the powder was predicted on the basis of free flowness of product under accelerated storage condition (38 ± 1 °C, 90 ± 1% relative humidity) and was calculated to be 33.87, 42.58 and 51.05 days in BOPP, PP and AF, respectively. The storage stability of powder in terms of colour change was studied. The magnitude of colour change of Aloe vera gel powder during storage suggests that AF was better than BOPP and PP. The colour change of powder during storage followed first order reaction kinetics with a rate constant of 0.0444 per day for AF, 0.075 per day for BOPP and 0.0498 per day for PP.