Predicting the Glycemic Index of Biscuits Using Static In Vitro Digestion Protocols

Novel Fibre-Rich Breads Yield Improved Glucose Release Curves and Are Well Accepted by Children in Primary School Breakfast Clubs

BACKGROUND

The average fibre consumption of 4-10-year-old children in the UK is 14.6 g per day, with only 14% of these children reaching the 20 g recommended by the SACN (UK Scientific Advisory Committee on Nutrition), and this 'fibre gap' may be most pronounced in communities with the lowest socioeconomic status. School breakfast clubs target children from disadvantaged communities, but their provision may favour lower-fibre foods, due to perceptions that children will reject higher-fibre foods. Our research programme aims to increase the fibre density, digestive-metabolic quality and acceptability of school breakfast provision.

METHODS

In Study 1, we examined the in vitro digestion of four novel bread products, to determine the relationship between fibre content and glucose release profile, and assess their suitability for sustaining school activity. In Study 2, we introduced the Prograins breads, alongside higher-fibre breakfast cereals and fresh fruit, to primary school breakfast clubs.

RESULTS

The Prograins bread products yielded lower peaks and more sustained glucose release curves than the 'standard' white bread control. Many children liked and chose the intervention foods, and the average fibre content of children's breakfasts increased.

CONCLUSIONS

We conclude from this study that nutritious, fibre-rich bread products can be acceptable to children and that higher-fibre breakfast provision is feasible, and we recommend larger-scale intervention and assessment to validate these real-world findings.

Prediction of apparent total tract digestion of crude protein in adult dogs

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.