Physical-chemical characterization, microbiological and biocompounds of cashew pulp in industrial and freezing processing

Abstract This study aimed to evaluate the nutritional characteristics, bioactive compounds and microbiological quality during the processing and frozen storage of cashew pulps. Cashew pulps from 4 batches and 3 different sequential stages of industrial processing and storage (after pulping, after pulp thawing that was stored for 3 months in a drum, and 90 days after packaging in bugs and frozen storage at –20 °C) were obtained and submitted to the following analyses: pH, total soluble solids (TSS), color (L*, c* and H°), acidity, ascorbic acid, glucose reducing sugars, total phenols, antioxidant potential by reducing DPPH (1,1-diphenyl-2-picrylhydrazyl) and microbiological parameters (Fungi, psychrotrophic bacteria and coliforms). There was interaction between batches and processing steps for all evaluated parameters, except phenols in acetone extract. The acidity of all batches verified was below of the minimum value recommended by current legislation. Sugars, acidity, ascorbic acid and color were negatively affected during processing. The phenolic compounds presented slight modifications, with a slight increase between the first two stages. Although the antioxidant potential presented variations, there was no single response profile for all batches. High microbial counts were observed after pulping, however there were considerable reductions throughout the processing/storage.

摘要 本研究旨在评估腰果浆（cashew pulps）在加工与冷冻储存过程中的营养特性、生物活性成分及微生物质量。研究采集了4个批次的腰果浆，覆盖工业加工与储存的3个连续工序阶段：打浆后、转桶储存3个月后的浆体解冻后，以及装袋后于-20℃冷冻储存90天的样品，并对以下指标开展检测：pH值、总可溶性固形物（Total Soluble Solids, TSS）、色度（L*、c*及H°）、总酸度、抗坏血酸、葡萄糖还原糖、总酚类物质、基于DPPH（1,1-二苯基-2-苦基肼，1,1-diphenyl-2-picrylhydrazyl）自由基清除法的抗氧化活性，以及微生物学参数（真菌、嗜冷菌及大肠菌群）。除丙酮提取物中的总酚类物质外，所有检测指标均呈现批次与加工工序间的交互作用。所有批次的总酸度均低于现行法规推荐的最低限值。糖类、总酸度、抗坏血酸及色度在加工过程中受到负面影响。酚类化合物仅出现轻微变化，在前两个工序阶段间略有升高。尽管抗氧化活性存在波动，但所有批次并未呈现统一的响应模式。打浆后微生物数量较高，但在后续加工/储存过程中出现显著降低。