{"title":"Lemon Juice Formulations Modulate <i>In Vitro</i> Digestive Recovery of Spinach Phytochemicals.","authors":"Valerija Vujčić Bok, Ivana Šola, Gordana Rusak","doi":"10.17113/ftb.60.03.22.7104","DOIUrl":null,"url":null,"abstract":"<p><strong>Research background: </strong><i>Citrus limon</i> (L.) Burm lemon juice is rich in many important natural chemical components (flavonoids, citric acid and vitamin C) and its use in traditional medicine is well known. Formulations of lemon juice with fruit polyphenols in beverages have been investigated, but there is very little information about their ability to modulate the digestive behaviour of polyphenols. The goal of this study is to determine the stability and digestive availability of spinach (<i>Spinacia oleracea</i> L.) polyphenols by adding different volume fractions of lemon juice (0, 2, 5, 10 and 20%) during <i>in vitro</i> digestion.</p><p><strong>Experimental approach: </strong>The content of polyphenols and other abundant compounds including nitrates, oxalic acid and l-ascorbic acid in spinach formulation with various volume fractions of lemon juice were measured in predigested and digested samples using <i>in vitro</i> human digestion model. Antioxidant and α-amylase inhibitory activities of spinach lemon juice formulation were also measured.</p><p><strong>Results and conclusions: </strong>The highest increases in total polyphenols, total flavonoids, total phenolic acids, oxalic acid and nitrate content were noted in predigested and almost all digested spinach samples formulated with the highest volume fraction of lemon juice. In the same sample, the content of individual compounds significantly increased after salivary \u2028(l-ascorbic acid), initial (<i>p</i>-coumaric acid) and intestinal (quercetin) phase of digestion. High bioaccessibility of polyphenols and l-ascorbic acid in all phases of digestion was observed in almost all spinach lemon juice formulations, with the exception of nitrates in gastric and intestinal phases and oxalic acid in the intestinal phase, which had moderate bioaccessibility.</p><p><strong>Novelty and scientific contribution: </strong>For the first time the stability and digestive availability of spinach polyphenols, oxalic acid, nitrates and l-ascorbic acid were tested with the addition of different volume fractions of lemon juice. The pH of lemon juice and its \u2028l-ascorbic acid content increase the stability and availability of polyphenols in spinach lemon juice formulation during <i>in vitro</i> digestion. Antioxidant and α-amylase inhibitory activities increase in dose-dependent manner after lemon juice addition. Accordingly, spinach formulated with 20% of lemon juice appears as the best source of dietary polyphenols with antioxidant and antidiabetic activities and nitrates that may be used as a functional drink.</p>","PeriodicalId":12400,"journal":{"name":"Food Technology and Biotechnology","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9590261/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food Technology and Biotechnology","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.17113/ftb.60.03.22.7104","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Research background: Citrus limon (L.) Burm lemon juice is rich in many important natural chemical components (flavonoids, citric acid and vitamin C) and its use in traditional medicine is well known. Formulations of lemon juice with fruit polyphenols in beverages have been investigated, but there is very little information about their ability to modulate the digestive behaviour of polyphenols. The goal of this study is to determine the stability and digestive availability of spinach (Spinacia oleracea L.) polyphenols by adding different volume fractions of lemon juice (0, 2, 5, 10 and 20%) during in vitro digestion.
Experimental approach: The content of polyphenols and other abundant compounds including nitrates, oxalic acid and l-ascorbic acid in spinach formulation with various volume fractions of lemon juice were measured in predigested and digested samples using in vitro human digestion model. Antioxidant and α-amylase inhibitory activities of spinach lemon juice formulation were also measured.
Results and conclusions: The highest increases in total polyphenols, total flavonoids, total phenolic acids, oxalic acid and nitrate content were noted in predigested and almost all digested spinach samples formulated with the highest volume fraction of lemon juice. In the same sample, the content of individual compounds significantly increased after salivary (l-ascorbic acid), initial (p-coumaric acid) and intestinal (quercetin) phase of digestion. High bioaccessibility of polyphenols and l-ascorbic acid in all phases of digestion was observed in almost all spinach lemon juice formulations, with the exception of nitrates in gastric and intestinal phases and oxalic acid in the intestinal phase, which had moderate bioaccessibility.
Novelty and scientific contribution: For the first time the stability and digestive availability of spinach polyphenols, oxalic acid, nitrates and l-ascorbic acid were tested with the addition of different volume fractions of lemon juice. The pH of lemon juice and its l-ascorbic acid content increase the stability and availability of polyphenols in spinach lemon juice formulation during in vitro digestion. Antioxidant and α-amylase inhibitory activities increase in dose-dependent manner after lemon juice addition. Accordingly, spinach formulated with 20% of lemon juice appears as the best source of dietary polyphenols with antioxidant and antidiabetic activities and nitrates that may be used as a functional drink.
期刊介绍:
Food Technology and Biotechnology (FTB) is a diamond open access, peer-reviewed international quarterly scientific journal that publishes papers covering a wide range of topics, including molecular biology, genetic engineering, biochemistry, microbiology, biochemical engineering and biotechnological processing, food science, analysis of food ingredients and final products, food processing and technology, oenology and waste treatment.
The Journal is published by the University of Zagreb, Faculty of Food Technology and Biotechnology, Croatia. It is an official journal of Croatian Society of Biotechnology and Slovenian Microbiological Society, financed by the Croatian Ministry of Science and Education, and supported by the Croatian Academy of Sciences and Arts.