Juçara pulp: total phenolics content, increased antioxidant activity and viability of probiotic bacteria in yogurt

ABSTRACT The addition of juçara pulp as source of phenolic compounds in yogurt can modify the physico-chemical characteristics, contribute to antioxidant activity and interfere on the viability of probiotic bacteria and sensory acceptance. To evaluation the effect of the addition of juçara pulp in yogurt, was conducted an experiment in completely randomized design in subdivided parcels. The main plot was the pulp content (0, 5, 10, 15, 20 and 25%) and as sub-plot storage time 5 oC (1, 7, 14, 21 and 28 days). The average percentage of fat, ash, total dry extract and acidity of yogurt did not differ (P ≥ 0.05). The protein content decreased with the increase in pulp content, ranging from 4.07% (F0) 2.9% (F25%). The total phenolic content and antioxidant activity were higher in yogurt with 25% of pulp, reaching 117.84 mg values of AGE/100 g and 6.95 Trolox µmol/g, respectively. As well as the count of probiotic bacteria, which ranged from 3.17 log CFU g-1 (F0) 6.34 log CFU g-1 (F25%) in yogurts after 28 days of storage. Adding the Juçara pulp favored the multiplication and viability of probiotic bacteria, contributed to increase the total phenolic content and antioxidant activity in yogurts that have good sensory acceptance by the consumer.

摘要
在酸奶中添加尤萨拉果肉（juçara pulp）作为酚类化合物来源，可改变其理化特性、提升抗氧化活性，并对益生菌（probiotic bacteria）的存活能力与消费者感官接受度产生影响。为评估尤萨拉果肉添加对酸奶的影响，本研究采用裂区完全随机设计开展实验。主区因素为果肉添加量（0、5、10、15、20及25%），裂区因素为5℃下的贮藏时间（1、7、14、21及28天）。
酸奶的脂肪、灰分、总干提取物及酸度的平均占比无显著差异（P≥0.05）。蛋白质含量随果肉添加量升高而降低，范围为4.07%（F0组）至2.9%（F25组）。添加25%果肉的酸奶总酚含量与抗氧化活性更高，分别可达117.84 mg AGE/100g与6.95 µmol Trolox/g。贮藏28天后的酸奶中，益生菌计数范围为3.17 log CFU g⁻¹（F0组）至6.34 log CFU g⁻¹（F25组）。
添加尤萨拉果肉可促进益生菌的增殖与存活能力，提升酸奶的总酚含量与抗氧化活性，且所得产品拥有良好的消费者感官接受度。