Fruit enzymatic browning (EB) inhibition continues to be a challenge in the Food Industry. This physiological disorder results mainly from the oxidation of natural phenolic compounds by polyphenoloxidase (PPO) and peroxidase (POX) leading to the formation of brown pigments. EB can be controlled with the application of antioxidants, reducing/inhibiting the activity of these oxidative enzymes. In this study, strawberry tree (leaves and branches) and apple byproduct were the natural-based extracts (NES) selected, as potential tissue browning inhibitors, within a first screening of fifteen natural-based extracts with antioxidant properties. Phenolic profile, total phenolic content and antioxidant activity of the selected extracts were also performed as well as their depletion effect on the oxidative enzyme’s activity and browning inhibiton in fresh-cut pears. Strawberry tree extracts (leaves and branches) revealed higher total phenolic content (207.97 ± 0.01 mg GAE.g_NES⁻¹ and 104.07 ± 16.38 mg GAE.g_NES⁻¹, respectively), confirmed by the plethora of phenolic compounds identified by LC-ESI-UHR-QqTOF-HRMS and quantified by HPLC. This phytochemical composition was reflected in the low IC₅₀ against PPO and POX obtained. Despite the lower phenolic content (6.76 ± 0.11 mg GAE.g_NES⁻¹) and antioxidant activity (IC₅₀ = 45.59 ± 1.34 mg mL⁻¹), apple byproduct extract showed potential in delaying browning. This study highlights the opportunity of byproducts and agricultural wastes extracts as novel anti-browning agents.

中文翻译：

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基于天然的抗氧化剂提取物，可以缓解水果褐变。

水果酶促褐变（EB）抑制仍然是食品工业中的一个挑战。这种生理失调主要是由于天然酚类化合物被多酚氧化酶（PPO）和过氧化物酶（POX）氧化导致棕色颜料的形成。EB可以通过使用抗氧化剂来控制，从而减少/抑制这些氧化酶的活性。在这项研究中，草莓树（叶子和树枝）和苹果副产品是天然提取物（NES），被选作15种具有抗氧化特性的天然提取物的首次筛选，作为潜在的组织褐变抑制剂。酚醛型材 还对所选提取物的总酚含量和抗氧化活性进行了研究，并研究了它们对鲜切梨中氧化酶活性和褐变抑制的消耗作用。草莓树提取物（叶子和树枝）的总酚含量较高（207.97±0.01 mg GAE.g_NES ^-1和104.07±16.38 mg GAE.g _NES ^-1），通过大量的酚类化合物确定，这些化合物通过LC-ESI-UHR-QqTOF-HRMS鉴定并通过HPLC定量。这种植物化学成分反映在针对获得的PPO和POX的低IC _50上。尽管较低的酚类含量（6.76±0.11 mg GAE.g _NES ^-1）和抗氧化剂活性（IC ₅₀ = 45.59±1.34 mg mL ^-1），苹果副产物提取物仍具有延迟褐变的潜力。这项研究强调了副产品和农业废物提取物作为新型抗褐变剂的机会。