Effect of Drying Techniques on the Physical, Functional, and Rheological Attributes of Isolated Sunflower Protein and Its Hydrolysate

The influence of freeze and convection (at 40 and 50 °C) drying on the physical, functional, and rheological attributes of sunflower protein (SP) and its hydrolysate (SPH) was investigated. Compared with convectively-dried samples, the lightness, turbidity, bulk density, and particle size values of the freeze-dried SP and SPH were substantially higher, but the browning index was lower (p < 0.05). Additionally, freeze-dried samples exhibited good solubility and foaming characteristics, whereas lower emulsion properties with the most pH values were observed. Furthermore, SPHs possessed higher solubility as well as foamability over SPs under varying pH values (2.0–10.0), whilst reduction in the emulsion activity index was clearly observed (p < 0.05). Convectively-dried powders exhibited greater viscosity and consistency coefficient; and significantly lower flow behavior index of dispersions, relative to the respective freeze-dried preparations, indicating that dehydration methods influenced the flow behavior of the investigated samples. From a molecular weight analysis, convectively-dried samples at various temperatures were characterized with high proportion of small-sized particles at ≤1 kDa fractions over the respective powders obtained by freeze drying. The observations made, thus, would benefit food processors and manufacturers in electing better dehydration technique based on the desired traits of SP and SPH powders for successful application in food product formulations.

PSV-B-26 Performance of sunflower protein meal and dried yeast as secondary protein sources in feline diets

The objectives of this study were to assess graded inclusions of sunflower protein meal (SPM; crude protein: 54%, crude fat: 11%, crude fiber: 4%) and dried yeast (DY; crude protein: 50%, crude fat: 3%, crude fiber: 2%) on nutrient digestibility, stool quality, and palatability in adult cats. Both SPM and DY were included at 5% and 10% in replacement of pea protein in a high-protein, chicken-based feline diet to maintain equal macronutrient concentrations across all test diets (formulated to 41% crude protein, 18% crude fat, 3% crude fiber). The study was approved and followed by the facility’s Institutional Animal Care and Use Committee. A standard 2-bowl palatability test over a 2-day period was executed with adult cats (n = 30 each) to determine intake ratios between test diets (5% and 10% SPM or 5% and 10% DY), and test diets vs. control. Total tract nutrient digestibility was evaluated (n = 8 per diet) with 5 days of diet acclimation followed by 5 days of total fecal collection. Stool quality was evaluated on a 1–5 scale, where 1 = hard/formed and 5 = non-formed/diarrhea. All data were analyzed by ANOVA (SAS v9.4) and T-tests post-hoc (Minitab 18). Palatability and stool quality were similar (P &gt; 0.05) between all diets. Protein digestibility was lower for DY-containing diets, compared with control (5% DY at P = 0.0083 and 10% DY at P = 0.0336), but not significantly different for SPM diets (P &gt; 0.05). However, average protein digestibility was &gt;88% across all diets. The alternative protein sources tested showed merit for inclusion to diversify ingredient sources while maintaining palatability in cat diets.

PSV-B-25 Performance of sunflower protein meal and dried yeast as secondary protein sources in canine diets

The objectives of this study were to assess graded inclusions of sunflower protein meal (SPM; crude protein: 54%, crude fat: 11%, crude fiber: 4%) and dried yeast (DY; crude protein: 50%, crude fat: 3%, crude fiber: 2%) on nutrient digestibility, stool quality, and palatability in adult dogs. Both SPM and DY were included at 5% and 10% in replacement of pea protein in a high-protein, chicken-based canine diet to maintain equal macronutrient concentrations across all test diets (formulated to 35% crude protein, 15% crude fat, 3% crude fiber). The study was approved and followed by the facility’s Institutional Animal Care and Use Committee. A standard 2-bowl palatability test over a 2-day period was executed with adult dogs (n = 30 each) to determine intake ratios (IR) between test diets (5% and 10% SPM or 5% and 10% DY), and test diets vs. control. Total tract nutrient digestibility was evaluated (n = 8 per diet) with 5 days of diet acclimation followed by 5 days of total fecal collection. Stool quality was evaluated on a 1–5 scale, where 1 = hard/formed and 5 = non-formed/diarrhea. All data were analyzed by ANOVA (SAS v9.4) and T-tests post-hoc (Minitab 18). With P &lt; 0.05 considered statistically significant, no differences were observed between diets for protein digestibility (all &gt;84% avg) or stool scores (all averages between 2.25–2.50). For DY-containing diets, no significant differences in IR were noted vs. control (IRs = 35:65, 5% DY vs control; 40:60, 10% DY vs. control). However, palatability of control was preferred vs. SPM-containing diets (P&lt; 0.05; IRs = 19:81, 5% SPM vs. control; 29:71, 10% SPM vs. control). Overall, detriments in protein digestibility and stool quality were not evident with DY and SPM, suggesting their viability as alternative protein sources in dog diets.

Preliminary Characterisation of Wastes Generated from the Rapeseed and Sunflower Protein Isolation Process and Their Valorisation in Delaying Oil Oxidation

Since rapeseed and sunflower meals are two of the most representative oilseed crops in the world, this study was focused on ethanol-wash solutes (EWS) obtained as wastes from the protein isolation process of rapeseed and sunflower meals. These meals have been previously valorised; however, the use of the EWS is unexplored. The present study is aimed at the characterisation of their phenolic profile, and antioxidant capacity for preventing lipid oxidation in rapeseed, sunflower, and soybean oil, which has been used as a reference oil. The sunflower EWS exhibited more total phenolic compounds (TPC) and antioxidant activity (119.39 ± 1.13 mg GA/g and 193.97 ± 9.77 mg TE/g, respectively) than the rapeseed one (103.44 ± 5.94 mg GA/g and 89.51 ± 3.17 mg TE/g). The phenolic identification showed hydroxybenzoic and protocatechuic acid in the rapeseed EWS, and pyrogallol and caffeic acid in the sunflower EWS, as the main representative phenols. Both EWS at 15% increased significantly (p < 0.05) the oxidative stability of the oils in the Rancimat equipment with values of antioxidant activity index (AAI) from 1.01 to 1.20, depending on the type of oil employed. In conclusion, the rapeseed and sunflower EWS showed great potential, and they could be used as a source of natural antioxidants within the food industry, replacing the synthetic ones, and promoting the circular economy since they are agro-food wastes.