Fish Protein and Lipid Interactions on the Digestibility and Bioavailability of Starch and Protein from Durum Wheat Pasta

This research focussed on the utilisation of salmon protein and lipid to manipulate pasta's glycaemic index and protein digestibility. Salmon fish (Oncorhynchus tschawytscha) powder (SFP) supplemented pasta flour in amounts from 5% to 20% (w/w). Inclusion of SFP lead to a significant reduction in starch digestibility and hence the potential glycaemic values of pasta (experimental pasta being up to 143% lower than control values). SFP addition to pasta increased the release of phenolic compounds from pasta during both gastric digestion (179%) and pancreatic digestion (133%) in comparison to the control sample. At the same time, the antioxidant activity of the digested pasta was increased by up to 263% (gastric) and 190% (pancreatic) in comparison to durum wheat pasta alone. Interestingly, although protein levels increased with incorporation of SFP, the digestibility values of the protein decreased from 86.41% for the control pasta to 81.95% for 20% SFP pasta. This may indicate that there are interactions between phenols and protein in the pasta samples which affect overall protein digestibility levels.

Protein, Amino Acid, Fatty Acid Composition, and in Vitro Digestibility of Bread Fortified with Oncorhynchus tschawytscha Powder

This study investigated protein, amino acid, fatty acid composition, in vitro starch and protein digestibility, and phenolic and antioxidant composition of bread fortified with salmon fish (Oncorhynchus tschawytscha) powder (SFP). The proximate composition in control and SFP breads ranged between (34.00 ± 0.55–31.42 ± 0.73%) moisture, (13.91 ± 0.19–20.04 ± 0.10%) protein, (3.86 ± 0.02–9.13 ± 0.02%) fat, (2.13 ± 0.02–2.42 ± 0.09%) ash, (80.10 ± 0.018–68.42 ± 0.11%) carbohydrate, and (410.8 ± 0.18–435.96 ± 0.36 kcal) energy. The essential amino acids of the control and SFP breads ranged between 261.75 ± 9.23 and 306.96 ± 6.76 mg/g protein, which satisfies the score recommended by FAO/WHO/UNU (2007). Protein digestibility of the products was assessed using an in vitro assay. The protein digestibility, comma, amino acid score, essential amino acid index, biological value, and nutritional index ranged between 79.96 ± 0.65–80.80 ± 0.99%, 0.15 ± 0.06–0.42 ± 0.06%, 62.51 ± 1.15–76.68 ± 1.40%, 56.44 ± 1.05–71.68 ± 1.10%, 8.69 ± 0.10–15.36 ± 0.21%, respectively. Control and SFP breads contained 60.31 ± 0.21–43.60 ± 0.35 g/100 g total fatty acids (saturated fatty acids) and 13.51 ± 0.10–17.00 ± 0.09 g/100 g total fatty acids (polyunsaturated fatty acids), and SFP breads fulfil the ω-6/ω-3 score recommended by food authority. There was a significant effect of SFP on bread-specific volume, crumb color, and textural properties. The in vitro starch digestibility results illustrate that the incorporation of SFP into wheat bread decreased the potential glycemic response of bread and increased the antioxidant capacity of bread. In conclusion, this nutrient-rich SFP bread has the potential to be a technological alternative for the food industry.