Dias Cindy, Fonseca Alexandre M A, Amaro Ana L, Vilas-Boas Ana A, Oliveira Ana, Santos Sonia A O, Silvestre Armando J D, Rocha Sílvia M, Isidoro Nélson, Pintado Manuela
Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua de Diogo Botelho, 1327, 4169-005 Porto, Portugal.
CICECO-Instituto de Materiais de Aveiro, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portuga.
Antioxidants (Basel). 2020 Aug 7;9(8):715. doi: 10.3390/antiox9080715.
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 and 104.07 ± 16.38 mg GAE.g, 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 IC against PPO and POX obtained. Despite the lower phenolic content (6.76 ± 0.11 mg GAE.g) and antioxidant activity (IC = 45.59 ± 1.34 mg mL), apple byproduct extract showed potential in delaying browning. This study highlights the opportunity of byproducts and agricultural wastes extracts as novel anti-browning agents.
水果酶促褐变（EB）的抑制一直是食品工业中的一项挑战。这种生理紊乱主要源于多酚氧化酶（PPO）和过氧化物酶（POX）对天然酚类化合物的氧化，导致褐色色素的形成。可以通过应用抗氧化剂来控制EB，降低/抑制这些氧化酶的活性。在本研究中，在对15种具有抗氧化特性的天然提取物进行的首次筛选中，选取草莓树（叶和枝）提取物和苹果副产品提取物作为潜在的组织褐变抑制剂。还对所选提取物的酚类成分、总酚含量和抗氧化活性进行了测定，并研究了它们对鲜切梨中氧化酶活性的消耗作用和褐变抑制效果。草莓树提取物（叶和枝）显示出较高的总酚含量（分别为207.97±0.01 mg GAE/g和104.07±16.38 mg GAE/g），通过LC-ESI-UHR-QqTOF-HRMS鉴定并经HPLC定量的大量酚类化合物证实了这一点。这种植物化学成分反映在对PPO和POX获得的低IC值上。尽管苹果副产品提取物的酚含量较低（6.76±0.11 mg GAE/g）且抗氧化活性较低（IC50 = 45.59±1.34 mg/mL），但它在延缓褐变方面显示出潜力。本研究突出了副产品和农业废弃物提取物作为新型抗褐变剂的机会。
