Consumption of dietary fibre (DF) may promote satiety and reduce the risk of many diseases, including heart diseases, diabetes and bowel cancer(Reference Lunn and Buttriss1). Despite current recommendations, DF consumption remains too low, possibly due to a lower sensory acceptance of fibre enriched products(Reference Grigor, Brennan and Hutchings2). Fava Bean Husks (FBHs) are a by-product of fava beans (FBs), currently used for livestock feed. They are high in fibre(Reference Lunn and Buttriss1) and could become a sustainable way of increasing the fibre content in staple food in Scotland(Reference Iriti and Varoni3). The aim of this research was to identify the impact of FBHs on satiety (Study 1) and consumer palatability and acceptance (Study 2), in a healthy young population.
Study 1 was a crossover randomised controlled trial (RCT) (n = 21; 10 males, 11 females) comparing the satiating effect of two iso-caloric plain bread breakfasts: 33% FBH enriched bread (FBB1) and control white bread (WB), providing 9.17 g and 2.12 g of DF per 100 g of bread, respectively. Hunger ratings were measured on Visual Analog Scales (VAS) at baseline and over 2h after bread consumption. Study 2 (n = 68; 42 males, 22 females, 4 N/A) compared the palatability and consumer acceptance (colour, crumb appearance, crust appearance, odour/aroma, texture, flavour, after-taste, overall impression and purchase possibility) of FBB1, FBB2 (37% FBHs, 9.80 g DF/100g), WB and two supermarket, white (SB1) and wholemeal (SB2) breads, in random order, using the 9-Point Hedonic Scale (9-PHS).
In study 1, FBB1 decreased hunger (p = 0.046), increased fullness (p = 0.031) and decreased the desire to eat (p = 0.033) compared to the WB (Figure 1), while the appetite score ([hunger + desire to eat + prospective consumption + 100 - fullness] / 4) was decreased without reaching significance (p = 0.07). There was no gender difference. In Study 2, the overall impression, flavour and after-taste were lower in FBB1 and FBB2 compared to WB, while texture was only rated lower in FBB2 (Table 1).
The results show that FB by-products present the potential to enrich staple foods with fibres (>9g/100g) and increase postprandial satiety. Whether reduced hunger is associated with a reduced subsequent energy intake, as previously demonstrated(Reference Howarth, Saltzman and Roberts4), remains to be established. This may provide a cost effective way to increase fibre intake in the Scottish population. Further research is needed to prevent the slight but significant decrease in consumer acceptance often associated with fibre enrichment of foods(Reference Grigor, Brennan and Hutchings2).