A Comparative Analysis of Lipid Digestion in Human Milk and Infant Formulas Based on Simulated In Vitro Infant Gastrointestinal Digestion

To investigate the lipid digestive behaviors of human and infant formulas and analyze the differences between them, we investigated the fat globule particle size distribution, lipolysis rate, and fatty acid release of infant formulas with different fat sources and human milk using an in vitro infant digestion model. The results suggested that the particle size in infant formula increased rapidly during gastric digestion and decreased significantly after intestinal digestion, whereas the particle size in human milk increased slowly during gastric digestion but increased rapidly during intestinal digestion (p < 0.05). Despite having a larger droplet size, human milk demonstrated a very high lipolysis rate due to the presence of MFGM. In terms of the distribution of fatty acids in digestion products, the proportion of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) in vegetable oil-based infant formulas was close to that of human milk. The amount of SFAs in milk fat-based infant formulas was significantly higher than that in human milk, and the content of MUFAs in all infant formulas was significantly lower than that in human milk (p < 0.05). After digestion, the most abundant fatty acid released by human milk was C18:2n6c, while the fatty acids released by infant formulas were SFAs, such as C14:0, C16:0, and C18:0.

Assessment of bio-availability of Cd, Pb, As and Tl via Gastric/Intestinal Digestion in Plants Collected From Different Kenyan Regions

In this study, total and bio-available levels of cadmium (Cd), Lead (Pb), arsenic (As) and Thallium (Tl) in 19 Kenya plants from two study sites (Manga and Borabu) were evaluated. ICP-MS technique was used to determine total Cd, Pb, As and Tl contents, while ultra-filtration and physiological extraction tests evaluated bio-accessibility of these elements. The plants had low concentrations; Cd (0.27±0.02 and 0.26±0.02), As (0.32±0.02 and 0.48±0.04), Tl (0.07± 0.02 and 0.06±0.01) and Pb (1.23±0.11 and 1.16±0.10) mg/kg in Manga and Borabu sites. However, sequential ultra-filtration showed more than 70% high molecular weight species (>10 kDa) predominated with Pb, Cd and Tl. The physiological based tests showed Cd, Pb, As and Tl extracted enzymatically were significantly higher (0.45±0.11, 0.46±0.12, 0.37±0.10 and 0.81±0.19µg/g) than aquatically extracted (0.32±0.07, 0.34±0.11, 0.26±0.08 and 0.50±0.27) µg/g, (p<0.05). Low bio-accessibility levels of these elements in medicinal plants justifies their use therapeutically.

In vitro Digestion and Swelling Kinetics of Thymoquinone-Loaded Pickering Emulsions Incorporated in Alginate-Chitosan Hydrogel Beads

The present work aimed to investigate the swelling behavior, in vitro digestion, and release of a hydrophobic bioactive compound, thymoquinone (TQ), loaded in Pickering emulsion incorporated in alginate-chitosan hydrogel beads using a simulated gastrointestinal model. In this study, oil-in-water Pickering emulsions of uniform micron droplet sizes were formulated using 20% red palm olein and 0.5% (w/v) cellulose nanocrystals-soy protein isolate (CNC/SPI) complex followed by encapsulation within beads. FT-IR was used to characterize the bonding between the alginate, chitosan, and Pickering emulsion. 2% (w/v) alginate-1% (w/v) chitosan hydrogel beads were found to be spherical with higher stability against structural deformation. The alginate-chitosan beads displayed excellent stability in simulated gastric fluid (SGF) with a low water uptake of ~19%. The hydrogel beads demonstrated a high swelling degree (85%) with a superior water uptake capacity of ~593% during intestinal digestion in simulated intestinal fluid (SIF). After exposure to SIF, the microstructure transformation was observed, causing erosion and degradation of alginate/chitosan wall materials. The release profile of TQ up to 83% was achieved in intestinal digestion, and the release behavior was dominated by diffusion via the bead swelling process. These results provided useful insight into the design of food-grade colloidal delivery systems using protein-polysaccharide complex-stabilized Pickering emulsions incorporated in alginate-chitosan hydrogel beads.

Effect of In Vitro Digestion on the Antioxidant Compounds and Antioxidant Capacity of 12 Plum (Spondias purpurea L.) Ecotypes

Spondias purpurea L. plum is a source of antioxidant compounds. Nevertheless, once they are consumed and go through the digestive system, these compounds may undergo changes that modify their bioaccessibility. This study aimed to evaluate the effect of in vitro gastrointestinal digestion on the total content of carotenoids (TCC), ascorbic acid (AA), phenolic compounds (TPC), flavonoids (TFC), anthocyanins (TAC), and antioxidant capacity (ABTS, DPPH) of 12 plum Spondias purpurea L. ecotypes. The plum samples were subjected to the InfoGest in vitro digestion model. TCC, AA, TPC, TFC, TAC, ABTS, and DPPH were significantly different (p ≤ 0.05) in each in vitro digestion stage. The gastric stage released the highest content of AA (64.04–78.66%) and TAC (128.45–280.50%), whereas the intestinal stage released the highest content of TCC (11.31–34.20%), TPC (68.61–95.36%), and TFC (72.76–95.57%). Carotenoids were not identified in the gastric stage whilst anthocyanins were lost at the end of the intestinal digestion. At the gastric stage, AA presented a positive and high correlation with ABTS (r: 0.83) and DPPH (r: 0.84), while, in the intestinal stage, TPC and TFC presented positive and high correlation with ABTS (r ≥ 0.8) and DPPH (r ≥ 0.8), respectively.

The Machinery of Digestion

This chapter discusses the machinery of digestion in giraffes. The shape of the mouth of giraffes, the shape and number of their teeth, the shape and size of their tongue and the arrangement of the muscles of eating are unique and have evolved to be perfectly suited to the task of browsing. Comminution of browse is eased by large volumes of saliva secreted from salivary glands that relative to body mass are small. The digestive tract of giraffes consists of a rumen, reticulum, and omasum in addition to the usual stomach and intestines found in any mammal. The forestomachs are smaller and the small and large intestines are longer than those of grazer-ruminants. The quality, succulence and consistency of browse reduces the need for prolonged rumination. Movement of browse through the rumen-reticulum is fast, and it is likely that a mixture of plant cell contents and saliva, can bypass the rumen via an esophageal groove, and be deposited directly into the stomach. 40% of daily energy (mainly in the form of volatile fatty acids) is provided by microbial fermentation of browse in the rumen, and 60% derives from intestinal digestion mainly of glucose), rather than the reverse as found in grazer-ruminants. Significant fermentation of undigested fiber (mainly hemicellulose) occurs in the large intestine. The combination of digestive processes results in very efficient use of the nutrients and an apparent digestibility of ~85%, which is high. To provide the browse needed to meet daily energy demand giraffes need a home range of ~60 km2.

Adaptation of in vitro methodologies to estimate the intestinal digestion of lipids in ruminants

The objective of this study was to adapt existing in vitro methodologies to determine the extent of intestinal digestion of corn oil (CO), canola oil (CA), and beef tallow (BT) via manipulation of incubation length and concentrations of lipase, bile, and calcium within a buffer solution. Unless otherwise stated, 0.5 g of each lipid source were incubated separately and in triplicate, with triplicate batch culture runs for each treatment in 40 mL of 0.5 M KH2PO4 (pH = 7.6) for 24 h with pancreatin (8 g/L), bovine bile (2.5 g/L), and CaCl2 (10 mM). Individually, concentrations of pancreatin, bile, and CaCl2, as well as incubation length were tested. To examine the use of this assay to estimate in vitro total tract digestion, a KH2PO4 solution with concentrated amounts to reach the same final concentrations of pancreatin, bile, and Ca were used as the third step in a three-step total tract digestibility procedure. Free glycerol and free fatty acid (FFA) concentrations were measured using colorimetric assays as indicators of digestion. Data wereanalyzed as a completely randomized block design (block = run), using the Glimmix procedure of SAS. For each lipid source, free glycerol increased with increasing pancreatin; however, FFA was lowest at 0 g/L pancreatin but was similar at 6, 8, and 10 g/L. Both glycerol and FFA were greater for 2.5 and 5 g/L of bile than for 0 g/L for each lipid source. Calcium concentration did not affect glycerol or FFA for either CO or CA; however, glycerol and FFA for BT were greater when calcium was included at 5 and 10 mM than at 0 mM. For all fat sources, free glycerol and FFA increased after 1 h until 12 h, but did not increase from 12 to 24 h. When a concentrated mixture was used following fermentation and acidification steps, digestibility using FFA concentration increased as compared to just adding buffer; however, free glycerol concentration was indeterminable. Thus, free glycerol and FFA can be used as indicators of lipid digestion when a lipid source is incubated for at least 12 h in a buffer solution containing 8 g/L pancreatin, 2.5 g/L bile, and 5 mM Ca when only estimating in vitro intestinal digestion; however, when utilizing this assay in a three-step in vitro total tract digestibility procedure, only FFA can be used.

Effects of Hydrothermal Processing Duration on the Texture, Starch and Protein In Vitro Digestibility of Cowpeas, Chickpeas and Kidney Beans

Legumes are a vital candidate in the fight for food security as a sustainable and nutritious food source. The current study systematically investigated the effects of hydrothermal processing of varying durations (15–120 min) on the texture, starch and protein digestibility of cowpeas (Vigna unguiculata), chickpeas (Cicer arietinum) and kidney beans (Phaseolus vulgaris). Texture analysis and in vitro oral-gastro-intestinal digestion of each legume was combined with kinetic modelling to explore the rate and extent of their changes observed during hydrothermal processing. All three legumes showed rapid initial texture decay in the first 30 min of processing. Chickpeas showed the fastest rate of texture degradation with processing duration, whereas texture degradation of kidney bean was slower but reached the lowest hardness value among all beans when processed up to 120 min. The rate of starch and protein digestion increased with prolonged processing duration, whilst showing an inverse relationship with texture values. The extent of starch digestion continually increased with processing duration for all three legumes, whereas the extent of protein digestion decreased after 60 min in cowpeas. This study systematically demonstrated how choosing different processing times can modulate the rate of texture degradation, starch and protein digestion in legumes. The findings of this study can aid consumers and manufacturers on optimal processing to achieve the desired texture or modulate starch and protein digestibility.