The Effect Of Technological Processing And Food Matrix On The Bioaccessibility Of Polyphenols From Fruit Juice

Polyphenols are rich in fruit, and have variety health effects on human, so fruit products attracted more and more consumers. C urrently researches on polyphenols are mostly concentrated on the chemical structure and biological function, but there is little research on the effect of industrial processing conditions and food ingredients on polyphenols bioavailability and efficacy. In fact, the bioavailability of polyphenols is a prerequisite for health benefits on the human body, because polyphenols will take place series of reactions in the processing and digestion process, the complex interactions can occur with other food ingredients, which would have a significant impact on polyphenols bioavailability and health benefits. Therefore, this paper choose five daily fruit(apple, grape, orange, pomelo, kiwi) as a raw material to explore the effect of high-pressure homogenization(HPHP, 250 MPa/10min), heating 80 ℃ for 30 min(T80) and heating 90 ℃ for 30 s(T90) processing, and added food ingredients(soy milk, skim milk, whole milk) in freshly squeezed juice on the total phenolic content, ABTS radical scavenging capacity and the content of the monomer phenolic. Study the changes in these indicators during digestive process by in vitro digestion, analyze the impact of processing conditions and food ingredients on the juice polyphenols bioavailability, design to improve the nutrition and health benefits of juice products, in order to develop new products and provide theoretical guidance for juice industry.First, choose three concentrated and freshly squeezed fruit juice as objects, analysis and identify juice phenolic monomer component, and compared their total phenolic content and ABTS radical scavenging ability in the digestive process. The results show that different fruit juices have various types of polyphenols, and may detected new polyphenols during digestion, due to digestion enzymes. Eight new phenolics(caftaric acid, cornflower-diglucoside, luteolin- glucoside, quercetin, caffeic acid, phlorizin, apigenin-glucosides, eriodictyol-rutinoside) is detected in concentrated apple juice during gastric digestion phase, seven new phenolics(caffeic acid, quinic acid, coumaric acid, peonidin, hesperetin, phlorizin, caftaric acid) is detected in freshly squeezed apple juice during small intestine digestion phase. The total phenolic content and antioxidant capability of concentrated apple juice in the digestive process show a gradual upward trend, but freshly squeezed apple juice declined at first, then rose, finally downward, which is different with concentrated apple juice. The total phenolic content and ABTS radical scavenging capacity of concentrated and freshly squeezed grape juice show a downward trend after a rise. The tot al phenolic content of concentrated and freshly squeezed orange juice is in consistent, which is a rise, then falling. The changes of ABTS radical scavenging capacity are different, ABTS radical scavenging capacity of concentrated orange juice significantly improved in the small intestine digestion phase(p < 0.05), but freshly squeezed orange juice decreased at first and then increased.Then, the paper respectively choose five freshly squeezed juice as subjects to explore the effect of processing technology and food ingredients on fruit polyphenol bioavailability. The results show that apple juice mainly contains chlorogenic acid, phlorizin, EGC G, hesperidin and so on. Heat treatment(T80, T90) and addition of whole milk, skimmed milk have no significant effect on apple juice polyphenols biological availability(p < 0.05), HPHP processing and addition of soy milk polyphenols reduced the apple juice biological availability of 29.5 % and 26.2 %. Grape juice mainly contains caffeoyltrataric acid, epicatechin, procyanidin and protocatechuic-glucoside. Heat treatment(T80, T90), addition of skimed milk and whole milk can significantly improve grape polyphenols bioavailability by 33.9 %, 27.3 %, 37.2 % and 29.5 %(p < 0.05), respectively, milk proteins have protective effects on protocatechuic- glucoside significantly. HPHP processing and add ition of soy milk have no significant effects(p > 0.05) on the bioavailability of grape polyphenols. Orange juice mainly contains naringin, caffeoyl- glucoside, hesperetin-rutinoside, naringenin-trisaccharide, luteolin- rutinoside, quercetin-trisaccharide. Skimmed milk improves the biological availability of orange juice polyphenols most, can be increased by 43 %. Heat treatment and addition of soy milk, skimmed milk and whole milk can make orange juice polyphenols biological availability increased by 13.3 %- 29.1 %, HPHP treatment has no significant effect on it(p > 0.05). Pomelo juice mainly contains naringenin-7-rutinoside, isorhamnetin-3-O-rutinoside, ferulic acid- glucoside, naringenin-rutinoside- glucoside, proanthocyanidin, proanthocyanidin- glucoside and so on. Skimmed milk and whole milk can improve the pomelo juice polyphenols biological availability of 59.6 % and 62.7 %, the protective effect of whole milk on all phenolics is remarkable, besides caffeoyl- glucoside. T90 heat treatment has no significant effect on pomelo juice polyphenols biological availability(p > 0.05). HPHP, T80 treatment and addition of soy milk can obviously decrease the biological availability of pomelo juice(p < 0.05). Kiwi juice mainly contains quinic acid, sinensetin, chlorogenic acid, chlorogenic acid and epigallocatechin and so on. HPHP and heat treatment have no significant effect on kiwi juice polyphenols biological availability(p > 0.05). Addition of soy milk and milk can improve the kiwi juice polyphenols biological availability of 21.7 %- 38.0 %, and remarkably protect all phenolics, besides chlorogenic acid.