Centre for Ecology, Evolution and Environmental Changes, Universidade de Lisboa, Lisboa, Portugal.
INIAV - Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal.
Food Sci Technol Int. 2022 Jul;28(5):421-429. doi: 10.1177/10820132211020837. Epub 2021 Jun 2.
In fresh-cut vegetables, plant tissues are often challenged by (a)biotic stresses that act in combination, and the response to combinatorial stresses differs from that triggered by each individually. Phenolic induction by wounding is a known response contributing to increase products phenolic content. Heat application is a promising treatment in minimal processing, and its interference on the wound-induced response is produce-dependent. In carrot, two-combined stress effects were evaluated: peel removal vs. shredding, and heat application (100 °C/45 s) vs. shredding, on changes in total phenolic content (TPC) during 10 days (5 °C). By applying the first stress combination, a decrease in TPC was verified on day 0 (∼50%), ascribed to the high phenolic content of peels. Recovery of initial fresh carrot levels was achieved after 7 days owing to phenolic biosynthesis induced by shredding. For the second combination, changes in TPC, phenylalanine-ammonia-lyase (PAL), and peroxidase (POD) activity of untreated (Ctr) and heat-treated (HS) peeled shredded carrot samples were evaluated during 10 days. The heat-shock did not suppress phenolic biosynthesis promoted by PAL, although there was a two-day delay in TPC increments. Notwithstanding, phenolic accumulation after 10 days exceeded raw material TPC content. Also, the decrease in POD activity (30%) could influence quality degradation during storage.
在新鲜切割的蔬菜中，植物组织经常受到（生物和非生物）胁迫的挑战，这些胁迫通常是联合作用的，而组合胁迫的反应与每种单独胁迫的反应不同。创伤诱导的酚类物质诱导是一种已知的反应，有助于增加产品的酚类物质含量。热应用是一种有前途的最小加工处理方法，其对创伤诱导反应的干扰因产品而异。在胡萝卜中，评估了两种组合胁迫的影响：去皮与切丝，以及热应用（100°C/45s）与切丝，在 5°C 下 10 天内总酚含量（TPC）的变化。通过应用第一种胁迫组合，在第 0 天（约 50%）检测到 TPC 下降，这归因于果皮的高酚含量。由于切丝诱导的酚类物质生物合成，在 7 天后恢复了初始新鲜胡萝卜水平。对于第二种组合，评估了未经处理（Ctr）和热处理（HS）去皮切丝胡萝卜样品在 10 天内 TPC、苯丙氨酸氨裂解酶（PAL）和过氧化物酶（POD）活性的变化。热休克并没有抑制 PAL 促进的酚类物质生物合成，尽管 TPC 增加有两天的延迟。尽管如此，10 天后的酚类物质积累超过了原料 TPC 含量。此外，POD 活性下降（30%）可能会影响储存期间的质量降解。
