The influence of pulsed electric fields (PEF) pre-treatment at different field strength (E = 1–5 kV/cm) and energy input (W_T = 5–10 kJ/kg) on the recovery yield of lycopene in either acetone or ethyl lactate from industrial tomato peels residues, was investigated. The rate of lycopene extraction in both solvents decreased with time and was predicted rather satisfactorily (R² = 0.96–0.99) by the Peleg's model. Micrograph of tomato peels showed that PEF induced size reduction and separation between the plant cells likely due to pore formation and leakage of intracellular matter. Coherently, PEF treatment (5 kV/cm, 5 kJ/kg) significantly enhanced the extraction rate (27–37%), the lycopene yields (12–18%) and the antioxidant power (18.0–18.2%) in either acetone and ethyl lactate extracts, as compared with untreated samples. However, acetone gave the highest lycopene yield. HPLC analyses revealed that all-trans lycopene was the main carotenoid extracted and no degradation/isomerization phenomena occurred. The results obtained in this work suggest that the application of PEF prior to solid-liquid extraction with environmentally friendly solvents could represent a sustainable approach for the valorization of industrial tomato peels residues.

Industrial relevance

Industrial processing of tomatoes generates large amount of by-products, mainly peels, which represent a cheap and abundant source of natural carotenoids, especially lycopene. The recovery lycopene from tomato peels residues is a crucial step for use in a wide range of industrial applications in food, cosmetic and pharmaceutical sectors as natural pigment and antioxidant. PEF pre-treatment allows to intensify the extractability of lycopene from of tomato processing by-products using environmentally friendly solvents, thus adding new value to the tomato processing chain, improving economic performances and decreasing waste problems.

中文翻译：

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脉冲电场辅助萃取从工业番茄加工副产物中回收番茄红素

脉冲电场（PEF）在不同场强（E = 1-5 kV / cm）和能量输入（W _T  = 5-10 kJ / kg）下的预处理对丙酮或番茄红素回收率的影响研究了工业番茄皮残留物中的乳酸乙酯。两种溶剂中番茄红素的提取率均随时间降低，并且预测令人满意（R ² = 0.96–0.99）。番茄皮的显微照片显示，PEF可能导致植物细胞之间的大小减小和分离，这可能是由于孔的形成和细胞内物质的泄漏所致。相干地，PEF处理（5 kV / cm，5 kJ / kg）显着提高了丙酮和丙酮中的提取率（27-37％），番茄红素产率（12-18％）和抗氧化能力（18.0-18.2％）。与未处理样品相比，乳酸乙酯提取物。然而，丙酮使番茄红素的产率最高。HPLC分析表明，全反式番茄红素是提取的主要类胡萝卜素，并且未发生降解/异构化现象。

行业相关性

西红柿的工业加工会产生大量的副产品，主要是果皮，这代表着便宜而丰富的天然类胡萝卜素，尤其是番茄红素的来源。从番茄果皮残留物中回收番茄红素是食品，化妆品和制药行业广泛使用的天然色素和抗氧化剂的关键步骤。PEF预处理可增强使用环保型溶剂从番茄加工副产品中提取番茄红素的能力，从而为番茄加工链增加新价值，改善经济表现并减少浪费问题。