Food Matrix Effects of Polyphenol Bioaccessibility from Almond Skin during Simulated Human Digestion

The goal of the present study was to quantify the rate and extent of polyphenols released in the gastrointestinal tract (GIT) from natural (NS) and blanched (BS) almond skins. A dynamic gastric model of digestion which provides a realistic simulation of the human stomach was used. In order to establish the effect of a food matrix on polyphenols bioaccessibility, NS and BS were either digested in water (WT) or incorporated into home-made biscuits (HB), crisp-bread (CB) and full-fat milk (FM). Phenolic acids were the most bioaccessible class (68.5% release from NS and 64.7% from BS). WT increased the release of flavan-3-ols (p < 0.05) and flavonols (p < 0.05) from NS after gastric plus duodenal digestion, whereas CB and HB were better vehicles for BS. FM lowered the % recovery of polyphenols, the free total phenols and the antioxidant status in the digestion medium, indicating that phenolic compounds could bind protein present in the food matrix. The release of bioactives from almond skins could explain the beneficial effects associated with almond consumption

Understanding cycle tourism experiences at the Tour Down Under

Sport tourism experiences are subjective and emotional, laden with symbolic meaning. This study explores the experiences of participants who adopted the multiple roles of both an active participant and event spectator, within the parameters of one chosen sporting event. A professional cycling race event, the Tour Down Under in South Australia was chosen for this investigation, and 20 face-to-face individual interviews were conducted with cycle tourists. The three main themes emerging from the data were the interaction of people and temporary spaces on a sport tourism ‘stage’; the co-creation of authentic personal experiences and meanings; and identity reinforcement and the development of a sense of belonging. Consequently, a model for understanding sport event tourism experiences is proposed. The findings suggest that providing tourists with authentic and memorable experiences lies at the heart of what constitutes sport tourism. Whilst the results demonstrate that cycling events provide the individual with a sense of belonging or membership to a wider social group, they also illustrate that there is a continued need for more focused and nuanced approaches towards understanding sport tourism experiences that reflect the ever-increasing diversity and complexity of the interaction between sport, events and tourism

The effects of processing and mastication on almond lipid bioaccessibility using novel methods of in vitro digestion modelling and micro-structural analysis

A number of studies have demonstrated that consuming almonds increases satiety but does not result in weight gain, despite their high energy and lipid content. To understand the mechanism of almond digestion, in the present study, we investigated the bioaccessibility of lipids from masticated almonds during in vitro simulated human digestion, and determined the associated changes in cell-wall composition and cellular microstructure. The influence of processing on lipid release was assessed by using natural raw almonds (NA) and roasted almonds (RA). Masticated samples from four healthy adults (two females, two males) were exposed to a dynamic gastric model of digestion followed by simulated duodenal digestion. Between 7·8 and 11·1 % of the total lipid was released as a result of mastication, with no significant differences between the NA and RA samples. Significant digestion occurred during the in vitro gastric phase (16·4 and 15·9 %) and the in vitro duodenal phase (32·2 and 32·7 %) for the NA and RA samples, respectively. Roasting produced a smaller average particle size distribution post-mastication; however, this was not significant in terms of lipid release. Light microscopy showed major changes that occurred in the distribution of lipid in all cells after the roasting process. Further changes were observed in the surface cells of almond fragments and in fractured cells after exposure to the duodenal environment. Almond cell walls prevented lipid release from intact cells, providing a mechanism for incomplete nutrient absorption in the gut. The composition of almond cell walls was not affected by processing or simulated digestion

Challenges to understanding and measuring carotenoid bioavailability

AbstractCarotenoids are an excellent example of where poor understanding of food structure, complexity of behaviour during digestion, and inter-individual differences in response, lead to misinterpretation of study results. Four challenges associated with understanding and measuring carotenoid bioavailability are discussed: release of carotenoids from food structure and processing into an absorbable form (bioaccessibility), passage of carotenoids from gut lumen into the body (absorption), interpreting plasma response and inter-individual variation.Bioaccessibility of carotenoids is governed by characteristics of the food matrix, which affect the efficiency of physical, enzymic and chemical digestion. Carotenoids used as colorants are likely to be better absorbed because of the form in which they are dispersed in food. Extent of absorption of carotenoid supplements will depend on the proximity of dosing to the consumption of a fat-containing meal. Release of carotenoids from food plants occurs only when the plant cell is fractured and this occurs only during food preparation, processing and/or mastication, not during digestion. Following release from the food matrix, the major limiting factor is solubility of carotenoids in digesta.Absorption studies are best carried out by measuring chylomicron carotenoid excursion, with modelling of chylomicron turnover rate. In this way, inter-individual differences in lipoprotein metabolism can, in part, be taken into account before formulating conclusions on the rate and extent of absorption