Paola Fortunati

Cooking quality and starch digestibility of gluten free pasta using new bean flour

The use of rice/leguminous blend may be nutritionally convenient in gluten free product manufacturing. Gluten free spaghetti was prepared with rice flour and different concentrations of bean flour (included at levels of 0%, 20% and 40%, w/w) derived from a new developed white-seeded low phytic acid and lectin free (ws+lpa+lf) bean cultivar. Protein, ash and dietary fibre contents increased linearly (P<0.05) while total starch decreased quadratically (P<0.05) with the inclusion of ws+lpa+lf bean flour. The colour of spaghetti was influenced (P<0.05) by ws+lpa+lf bean inclusion. With respect to 0% spaghetti, the inclusion of ws+lpa+lf bean increased linearly (P<0.05) the optimal cooking time and the water absorption capacity, without affecting cooking loss and texture properties. The ws+lpa+lf bean inclusion increases quadratically (P<0.05) the resistant starch content, while decreasing quadratically (P<0.05) the in vitro glycemic index. The partial replacement of rice flour with bean flour can favourably be used in gluten free spaghetti formulation.

Use of principal factor analysis to generate a corn silage fermentative quality index to rank well- or poorly preserved forages

BACKGROUND To investigate corn silage fermentative quality, a principal factor analysis was carried out on a database consisting of 196 corn silages sampled from the core, lateral and apical parts of silo feed-out face and characterised by 36 variables. Eleven principal factor components (PCs) were retained and interpreted. Two PCs were related to chemical and digestibility variables; four PCs were characterised by end-products associated with clostridia, heterolactic, homolactic or aerobic fermentations; two PCs were associated with mycotoxins produced by Penicillium roqueforti or by Aspergillus fumigatus and Fusarium spp., while three PCs explained ensiling procedures adopted to store corn silages. RESULTS Lower (P < 0.05) yeast or mould counts and greater (P < 0.05) aerobic stability were measured in core than in peripheral samples. Excluding PCs related to ensiling procedures, other PCs were able to predict microbiological counts, aerobic stability or biogenic amine content as verified by multiple linear regression analysis. Based on these results, several corn silage quality index calculations were computed by using a summative equation approach in which different PCs as well as diverse relative weights multiplying each PCs were combined. To compute definitive index calculation, only PCs explaining clostridia, heterolactic and homolactic fermentations were used with relative weights of 30%, 50% and 20%. CONCLUSIONS The new proposed fermentative quality index was highly correlated to parameters related to corn silage fermentative quality, such as microbiological counts, aerobic stability or biogenic amines and it properly discriminated well- and poorly preserved forages.

Exploitation of alfalfa seed (Medicago sativa L.) flour into gluten-free rice cookies: Nutritional, antioxidant and quality characteristics

In an effort to increase the nutritional value of common gluten-free (GF) cereal-based foods, GF cookies using alfalfa seed flour (ASF), at different substitution levels to common rice flour (0% as control, 15%, 30% and 45% w/w), were produced. Crude protein, total dietary fibre, total polyunsaturated, total n-3 and n-6 fatty acid contents increased linearly (p<0.05) by raising the substitution levels of rice with ASF. The hardness, the total phenolic content, the in vitro antioxidant capacity and the resistant starch increased linearly (p<0.05), whereas the starch hydrolysis index decreased linearly (p<0.05) by raising the substitution levels of rice flour with ASF. Despite the fact that ASF-substituted GF cookies had inferior sensory attributes compared to the control, the score given by the panellists remained at fairly good levels for all tested parameters, showing acceptability of the substituted GF cookies.

Gluten free Maize Cookies Prepared with High-amylose Starch: In Vitro Starch Digestibility and Sensory Characteristics

In an effort to improve gluten-free (GF) cookies overall nutritional aspects, as a means of decreasing the glycemic index and increasing the resistant starch content, experimental GF maize cookies were formulated with a normal amylose GF maize flour mix (NAM) and increasing levels of high amylose maize starch flour (HAM) represented by substitution ratio of 0%, 25% and 50% on a total flour (NAM+HAM) basis. Chemical composition, in vitro starch digestibility and sensory evaluation were carried out. Dietary fibre, total starch and amylose contents increased (p<0.05) when the level of HAM increased in the recipe for GF cookies. Both resistant starch and slowly digestible starch increased (p<0.05), whereas rapidly digestible starch and available starch levels decreased (p<0.05) when the level of HAM increased in the formulation. Slower rate of starch hydrolysis (up to minus 66.0%; p<0.05) and lower predicted glycemic index (up to minus 35.0%; p<0.05) were recorded when HAM increased in the composite. No differences were reported in the sensory profile and in the overall acceptability of GF maize cookies formulated with increasing levels of HAM. Taking together, present in vitro findings suggest that the partial substitution of NAM with HAM contributed to formulate GF maize cookies with slowly digestible starch properties without affecting overall sensory attributes.

Exploitation of common bean flours with low antinutrient content for making nutritionally enhanced biscuits

Consumption of legumes is associated with a number of physiological and health benefits. Legume proteins complement very well those of cereals and are often used to produce gluten-free products. However, legume seeds often contain antinutritional compounds, such as phytate, galactooligosaccharides, phenolic compounds, lectins, enzyme inhibitors, whose presence could affect their nutritional value. Screening natural and induced biodiversity for useful traits, followed by breeding, is a way to remove undesirable components. We used the common bean cv. Lady Joy and the lpa1 mutant line, having different seed composition for absence/presence of lectins,α-amylase inhibitor, (α-AI) and phytic acid, to verify the advantage of their use to make biscuits with improved nutritional properties. We showed that use of unprocessed flour from normal beans (Taylors Horticulture and Billò) must be avoided, since lectin activity is still present after baking, and demonstrated the advantage of using the cv. Lady Joy, lacking active lectins and having active α-AI. To assess the contribution of bean flour to biscuit quality traits, different formulations of composite flours (B12, B14, B22, B24, B29) were used in combinations with wheat (B14), maize (gluten-free B22 and B29), or with both (B12 and B24). These biscuits were nutritionally better than the control, having a better amino acid score, higher fiber amount, lower predicted glycemic index (pGI) and starch content. Replacement of cv. Lady Joy bean flour with that of lpa1, having a 90% reduction of phytic acid and devoid of α-AI, contributed to about a 50% reduction of phytic acid content. We also showed that baking did not fully inactivate α-AI, further contributing to lowering the pGI of the biscuits. Finally, data from a blind taste test using consumers indicated that the B14 biscuit was accepted by consumers and comparable in terms of liking to the control biscuit, although the acceptability of these products decreased with the increase of bean content. The B22 gluten-free biscuits, although received liking scores that were just above the middle point of the hedonic scale, might represent a good compromise between health benefits (absence of gluten and lower pGI), expectations of celiac consumers and likeness.