Carbohydrate digestion and predicted glycemic index of bakery/confectionary ex-food intended for pig nutrition

Abstract

This study evaluated the predicted glycemic index (pGI) in former food products (FFPs), and in two pig compound feeds formulated with or without the inclusion of FFPs. Six samples of FFPs and two pig compound feeds were used. FFPs were based on bakery and confectionary exfood, while the pig compound feed was formulated by substituting 30% of cereals with FFPs (Feed FFP30%). All samples were analysed using an in vitro Englyst assay that simulates gastric and small intestinal digestion, and which has been proposed to determine the hydrolysis index (HI) and predict the glycemic index (pGI) of cereal-based foods introduced into pig diets. Corn meal, heat processed wheat and a conventional pig compound feed (Feed CTR) were included as control feed ingredients. In the assay, white bread was used as reference material. The results differentiated between two main groups of samples, namely: low HI samples with an HI lower than 100 including corn meal, Feed CTR, Feed FFP30%, flaked wheat and FFP4; and high HI samples including all the other FFPs tested. The same classification can be adopted for pGI. Thus combining HI and pGI results suggests that most of the FFPs tested in the present study were characterised by a high glycemic index potential which seems to be linked to the starch/ sugars HI. The inclusion of FFPs in a commercial compound feed, and its effect on HI and pGI, merit further investigations. HIGHLIGHTS Ex-Food are food waste biomasses upgraded to feed ingredients; they are characterised by quick carbohydrates digestion and high glycemic index.

Potentials and Challenges of Former Food Products (Food Leftover) as Alternative Feed Ingredients

“…Processing techniques (e.g., thermal processing, extrusion cooking etc.) are able to affect both digestibility and absorption of digested carbohydrates [13], which in turn have a major impact on the glycaemic index [10]. These dietetics features have been investigated by Ottoboni et al [13], who measured hydrolysis index (HI), predicted glycaemic index (pGI), and the time trend in carbohydrate digestion (k), in FFPs in comparison with common cereals.…”

“…are able to affect both digestibility and absorption of digested carbohydrates [13], which in turn have a major impact on the glycaemic index [10]. These dietetics features have been investigated by Ottoboni et al [13], who measured hydrolysis index (HI), predicted glycaemic index (pGI), and the time trend in carbohydrate digestion (k), in FFPs in comparison with common cereals. Results obtained indicated that all parameters related to carbohydrate digestion (i.e., HI, pGI and k) were always higher in ex-food compared to conventional cereals feed ingredients such as unprocessed corn [13] (Figure 2).…”

“…These dietetics features have been investigated by Ottoboni et al [13], who measured hydrolysis index (HI), predicted glycaemic index (pGI), and the time trend in carbohydrate digestion (k), in FFPs in comparison with common cereals. Results obtained indicated that all parameters related to carbohydrate digestion (i.e., HI, pGI and k) were always higher in ex-food compared to conventional cereals feed ingredients such as unprocessed corn [13] (Figure 2). However, it is known that other constituents of the food matrix, such as proteins, lipids and fibres, play a significant role during processing which affects the physico-chemical characteristics of digesta and the final digestibility of starch [13].…”

Former food products have no detrimental effects on diet digestibility, growth performance and selected plasma variables in post-weaning piglets

“…A former foodstuffs producer based in the north of Italy has provided the complementary feed used for the formulation of the complete FFP diet. Based on our previous experience, the product with the highest in vitro digestibility (IVD) and the fastest carbohydrate digestion has been selected (Ottoboni et al 2019), given the nutritional needs of post-weaning piglets. The complementary feed was composed by, in descending order of inclusion: leftovers from the food industry (bakery products, pasta and confectionary products); wheat by-products (e.g.…”

“…152/2009. Additional information on the pure FFP used in this study (namely FFP2) can be found in Giromini et al (2017) and Ottoboni et al (2019).…”