| Popis: |
Orange juice may be a nutrient vehicle that helps to improve diet quality. The addition of whey allows the incorporation of high quality proteins. However, a good acceptability is necessary. The aims of the present study were: a) to assess the acceptability of a beverage prepared with orange juice (J) and whey powder (WP) at 7 g/100 g (J+WP7) or at 13 g/100 g (J+WP13); b) to measure available lysine content and ascorbic acid retention of the more accepted formulation, comparing the effect of HIPEF treatment (29 kV/cm, t(acum): 59 micros) with a conventional heat treatment at 75 degrees C, for 15 minutes (HT). The beverages were subjected to sensory evaluation (Friedman test). Available lysine was assessed by the Carpenter method, modified by Booth, and vitamin C by HPLC; minerals Na and K, by flame photometry; Ca, Mg and Zn by atomic absorption spectrometry. There were no significant differences between the acceptance of J and J+WP7. J+WP13 was significantly less accepted (p0.01), so it was discarded. Available lysine (mg/g protein) in untreated J+WP7 was 60.2 +/- 0.15; after treatments: 50.0 +/- 2.8 (HT) and 51.0 +/- 3.4 (HIPEF). The HIPEF treated J and (J+WP7) retained 100% and 98% of their vitamin C initial content and the HT treated, 91% and 88%, respectively. The amount of whey powder added to the orange juice conditioned the acceptability. The juice containing 7% of whey powder was well accepted, and after treatment by HIPEF, it retained a good nutritional quality, regarding available lysine, vitamin C retention and provision of mineral nutrients. |
