No abstract

Puroindoline a (Pin-a) and puroindoline b (Pin-b), two basic isoforms encoded by the Pina-D1 and Pinb-D1 loci respectively, involved in controlling grain texture in wheat, were isolated from starch granules of soft wheat cultivars using three different extraction procedures, and fractionated by acidic polyacrylamide gel electrophoresis (A-PAGE). Tris buffer containing 1% Triton X-114 extracted Pin-a and small amounts of Pin-b, whereas 1% SDS preferably extracted Pin-b. Large amounts of both puroindolines were isolated by a solution containing 50% propan-2-ol and 50 mM NaCl. This solution extracted reduced amounts of Pin-b and no traces of Pin-a from starch granules of 20 hard common wheats containing the null allele Pina-D1b. The absence of Pin-a was confirmed by immunostaining with an anti-Pin-a antiserum. With the exception of two cultivars, null Pin-a cultivars gave no PCR fragment with three primer pairs specific to either the coding region or the promoter region of Pina-D1a, suggesting that major changes had occurred at the Pina-D1 locus in these genotypes. Cultivars Fortuna and Glenman were unique in giving size-specific PCR fragments with all primer pairs for the allele Pina-D1a and showed a cytosine deletion at position 267 in the coding region of the Pin-a gene, which resulted in a TGA stop codon at position 361. However, there was no evidence of a mutated protein in the A-PAGE or SDS-PAGE patterns of Fortuna and Glenman. The novel gene, provisionally named Pina-D1c, is the first null allele due to a point mutation that has been identified at the Pina-D1 locus.

Brewers’ spent grain (BSG), the major by-product of the brewing industry, can be used as a functional ingredient to increase the nutritional value of cereal-based products. In this work, micronized BSG from the einkorn and tritordeum brewing processes were characterized and used to produce four macaroni pasta formulations enriched with BSG at ratios of 5 g and 10 g/100 g of semolina. Einkorn BSG showed the highest values for all the parameters analyzed—proteins, total dietary fiber (TDF) and total antioxidant capacity (TAC)—except for β-glucan. TDF increased up to 42 and 68% in pasta samples enriched with 10% of BSG from tritordeum and einkorn, respectively. The replacement of 10% of semolina with BSG from both cereals significantly increased the β-glucan content and TAC values. Finally, the addition of BSG from einkorn and tritordeum affected to a minimal extent the sensory properties of cooked pasta, which showed higher values of optimal cooking time and cooking loss, but lower total organic matter compared to semolina pasta. Results from the sensorial judgment fell in the good quality ranges for durum wheat pasta; the incorporation of 10% of einkorn BSG resulted in the best compromise in terms of technological, nutritional and sensorial aspects of enriched pasta.