Influence of the type of packaging on textural properties of minimally processed yellow Peruvian roots

ABSTRACT The textural properties of minimally processed products indicate its quality, and the package is fundamental to maintain the conservation of these foods. The aim of this study was to evaluate texture alterations that occur during the storage period of minimally processed yellow Peruvian roots, using texture profile analysis (TPA) and relaxation, in function of four types of plastic packaging, combined to refrigeration. The roots were selected, sanitized, peeled and sliced. The processing continued with final sanitization, rinsing and immersion in ascorbic and citric acid solution. The slices were centrifuged and packed in expanded polystyrene trays covered with PVC film, and in high-density polyethylene bags (HDPE), polypropylene bags (PP) and multilayer polyolefin bags for vacuum, and stored at 5 ± 2 ºC and 90 ± 5% relative humidity during 12 days. For the TPA, the parameters of interest were hardness and adhesiveness, automatically calculated from the force curves (F) x time (s). For modeling the relaxation process, the generalized Maxwell model was used. The slices packed in PP and vacuum showed higher hardness and normalized force in the balance (0.7502 and 0.7580, respectively), indicating that they were more elastic, better preserving the quality during storage than slices packed in other packaging.

摘要
轻加工食品的质构特性可反映其品质，而包装对维持这类食品的保鲜效果至关重要。本研究旨在采用质构剖面分析（texture profile analysis, TPA）与松弛试验，结合四种塑料包装类型及冷藏条件，评估轻加工秘鲁黄根在贮藏期间的质构变化。
试验原料先经过挑选、消毒、去皮与切片处理，随后进行末次消毒、漂洗，并浸没于抗坏血酸与柠檬酸混合溶液中。将切片经离心脱水后，分别装入覆有聚氯乙烯（PVC）膜的发泡聚苯乙烯托盘、高密度聚乙烯（HDPE）袋、聚丙烯（PP）袋以及真空用多层聚烯烃袋，并在温度5±2℃、相对湿度90±5%的条件下贮藏12天。
在质构剖面分析中，本研究关注的参数为硬度与粘附性，其数值可由力-时间（F-s）曲线自动计算得到。松弛过程的建模采用广义麦克斯韦模型。
采用PP包装与真空包装的切片，其平衡态硬度与归一化力分别为0.7502和0.7580，数值更高，表明此类包装的切片弹性更佳，在贮藏期间相比其他包装的切片能更好地保留产品品质。