Effect of In Vitro Gastrointestinal Digestion on Amino Acids, Polyphenols and Antioxidant Capacity of Tamarillo Yoghurts

Abstract

Laird’s Large tamarillo powder is high in protein (10%) essential amino acids (EAAs), gamma-aminobutyric acid (GABA) and polyphenols (0.6% phenolics plus anthocyanins) and fibre 25%. This study aimed to investigate, using a standardized static in vitro digestion model, the stability of amino acids and antioxidant capacity of polyphenols in yoghurt fortified with 5, 10 and 15% tamarillo powder either before (PRE) or after (POS) fermentation. Compared to plain yoghurt, the fruit polyphenols (rutinosides and glycosides) were retained and substantial increases in FEAAs (free essential amino acids), total phenolic content (TPC) and antioxidant activity were observed particularly at the end of intestinal phase of digestion. Together with SDS-PAGE results, peptides and proteins in tamarillo yoghurts were more easily digested and therefore may be better absorbed in the small intestine compared to the control. TPC and antioxidant activity of fortified yoghurts increased significantly after in vitro digestion. Relatively high bioaccessibilty of chlorogenic acid and kaempferol-3-rutinoside in digested PRE samples was observed. The results suggest that the yoghurt matrix might protect some compounds from degradation, increasing bioaccessibility and in the small intestine allow increased absorption and utilization possible. Fortification would deliver intact polyphenols and fibre to the large intestine and improve gut health. Further research of acceptability, shelf life, and then trials for health effects should be implemented.

Reformulating Bread Using Sprouted Pseudo-cereal Grains to Enhance Its Nutritional Value and Sensorial Attributes

“…Nonetheless, the amounts of bioaccesible GABA at the end of intestinal digestion were greater for BrKC as compared to BrWF. Resistance of GABA to the gastric environment (pH 1.2) and intestinal conditions was also reported earlier during simulated gastrointestinal digestion of a GABA-rich yogurt in agreement with our results [ 39 , 40 ].…”

“…Regular dietary intake of polyphenols, approximately 1–2 g per day, has been associated with chronic disease prevention [ 39 ]. Although there are no official recommendations for phenolic compounds, it is worth noting that a serving of 50 g of the developed BrKC could cover almost 25% of the reported mean daily intake (1 and 1.2 g/d) [ 40 ].…”

Simulated In Vitro Digestive Characteristics of Raw Yam Tubers in Japanese Diet: Changes in Protein Profile, Starch Digestibility, Antioxidant Capacity and Microstructure

“…This means that the Nebaristar could be a better option for the customer who expects to acquire more polyphenols when buying yams. This result was supported by previous studies on the changes in TPC of 23 commercially available vegetable juices during in vitro digestion using a similar evaluation method [ 35 ] and changes in the polyphenols of Tamarillo yoghurts [ 29 ]. During in vitro digestion, the protein and starch of the yam tuber were hydrolysed ( Figure 1 , Figure 2 and Figure 3 ) by the hydrolytic enzymes and pH changes, resulting in the release of polyphenols and an increase in the TPC.…”

“…Notably, Nebaristar contains 2.3 times more Arg than that in Nagaimo N-10, which was reported as a conditional essential amino acid for adults, with the functions of reproductive, cardiovascular and immune improvement [ 28 ]. The concentration and bioavailability of amino acids in the intestine could impact the protein metabolism at the splanchnic and peripheral tissues [ 29 ]. The current finding could serve as a nutritional reference to customers when buying yam tubers for the purpose of being eaten raw.…”

Effects of Green Tea Marinade in the Bioaccessibility of Tonalide and Benzophenone 3 in Cooked European Seabass

“…Frying grass carp fillets has also been reported to increase the content of released amino groups [ 34 ], and this increase was attributed to the hydrolysis of soluble proteins. The presence of proteins in fish, and the high levels of polyphenols in green tea marinade, can result in the formation of protein–polyphenol complexes, which can grow in size and even form sediments [ 35 ]. These complexes may also improve the stability of food emulsions on the shelf, prevent degradation of polyphenols, and improve target delivery to the intestinal tract [ 35 ].…”