Effect of orange fiber addition on yogurt color during fermentation and cold storage

Orange fiber obtained from orange juice by products was added to yogurt. Fiber (0%, 0.6%, 0.8%, and 1% closes and different fiber size: 0.417-0.701 and 0.701-0.991 mm) effects 017 color during yogurt fermentation and cold storage were studied. Overall composition, pH, acidity, syneresis, L*, a*, and b* values were determined. Sensory evaluation of yogurts was carried out. Fiber addition did not cause changes hi yogurt acidification and color during fermentation process, though decreased L* value and increased b* value of the milk. Color evaluation along fermentation is pH dependent (R > 0.870). pH decreased and syneresis increased along cold storage. Because of the acidification process, L* value decreased and a* and b* values increased in all yogurts. Yogurts with 1% fiber were significantly); different from the others along cold storage, presenting lower L*, higher a* and b* values, and lower syneresis. (c) 2005 Wiley Periodicals, Inc.