The physico-chemical properties of spray-dried pitaya peel powders kept at accelerated (45 ± 2°C) and room temperature (28 ± 2°C) for 14 weeks and 6 months, respectively were evaluated. Changes in physico-chemical properties of the peel powder were used as indicators of stability, while changes of the betacyanin pigment retention was used to calculate the shelf-life of the powder. Storage temperatures significantly (p < 0.05) affected all the studied parameters and Hunter a value had the most significant change. The pigment retention of peel powder was approximately 87% at 45°C and 89% at room temperature storage. Degradation of betacyanin pigment in the powder followed the first order reaction kinetics with the half-life (t1/2) of approximately 76 weeks at 45°C and 38 months at 28°C. The spray-dried pitaya peel powder had a solubility of 87 to 92% and low in powder hygroscopicity. The final Aw of the powder did not exceed 0.6 for both storage temperatures.
Malaysia is a surplus poultry producing country with well-established commercial slaughtering and processing plants. Immense quantity of heads, feet, viscera, blood and feathers are usually discarded and not optimally utilized. Chicken heads are rich in protein, and could be a potential source of gelatin. The aim of the present work was therefore to find a simpler, faster, cheaper and greener gelatin extraction technology as compared to current available methods of gelatin extraction from poultry heads. A comparison of three different gelatin extraction methods with alkaline-acid pretreatment (E1), single acid pretreatment (E2) and single alkaline pretreatment (E3) were studied to extract gelatin from chicken heads. E1 and E2 produced gelatins of Type A, while E3 produced gelatin of Type B. High bloom gelatin (>300 g) with