Ibrahim M Abd Elaleem’s scientific contributions

Apple and guava juice samples were homogenized with processing variables of speed (low, medium and high) limit and times (5, 10 and 15 min). The effects of homogenization on the physicochemical properties of apple and guava juice were studied. Hunter colour values (L*, a* and b*), pH, o Brix, titratable acidity, cloud value and browning index were measured. Ascorbic acid content was found to be lower in samples treated with homogenization than in the control. Retention of quality parameters was observed at the maximum treatment conditions of high speed limit for 15 min, indicating stability of colour during homogenization. Colour changes observed during homogenization were subtle (TCD from 2.14 to 2.00 in apple juice and from 3.01 to 3.92 in guava juice). Colour values (L*, a*, b*), Total Colour Difference (TCD), chroma, hue angle, browning index, ascorbic acid and turbidity were influenced by both homogenization speed limit and treatment time, with the effects observed being either individual or interactive. A homogenization treatment was demonstrated to be an effective technique to investigate the influence of homogenization on colour and quality retention. Homogenization could be used during apple and guava juice processing where colour and quality retention are desired.