Solvent Dependency of Sorghum Bran Phytochemicals Acting as Potential Antioxidants and Antibacterial Agents

Polyphenolic compounds in the combat of foodborne infections - An update on recent evidence

In recent years, the incidence of food-borne bacterial enteric diseases has increased worldwide causing significant health care and socioeconomic burdens. According to the World Health Organization, there are an estimated 600 million cases of foodborne illnesses worldwide each year, resulting in 420,000 deaths. Despite intensive efforts to tackle this problem, foodborne pathogenic microorganisms continue to be spread further. Therefore, there is an urgent need to find novel anti-microbial non-toxic compounds for food preservation. One way to tackle this issue may be the usage of polyphenols, which have received increasing attention in the recent years given their pleotropic health-promoting properties. This prompted us to perform a literature search summarizing studies from the past 10 years regarding the potential anti-microbial and disease-alleviating effects of plant-derived phenolic compounds against foodborne bacterial pathogens. The included 16 studies provide evidence that polyphenols show pronounced anti-bacterial and anti-oxidant effects against both Gram-positive and Gram-negative bacterial species. In addition, synergistic anti-microbial effects in combination with synthetic antibiotics were observed. In conclusion, phenolic compounds may be useful as natural anti-microbial agents in the food, agricultural, and pharmaceutical industries in the combat of foodborne infections.

Formulation and characterization of choline oleate-based micelles for co-delivery of luteolin, naringenin, and quercetin

Flavonoids have diverse beneficial roles that potentiate their application as nutraceutical agents in nutritional supplements and as natural antimicrobial agents in food preservation. To address poor solubility and bioactivity issues, we developed water-soluble micellar formulations loaded with single and multiple flavonoids using the biocompatible surface-active ionic liquid choline oleate. The food preservation performance was investigated using luteolin, naringenin, and quercetin as model bioactive compounds. The micellar formulations formed spherical micelles with particle sizes of <150 nm and exhibited high aqueous solubility (>5.15 mg/mL). Co-delivery of multiple flavonoids (luteolin, naringenin, and quercetin in LNQ-MF) resulted in 84.85% antioxidant activity at 100 μg/mL. The effects on Staphylococcus aureus and Salmonella enterica were synergistic with fractional inhibitory concentration indices of 0.87 and 0.71, respectively. LNQ-MF hindered the growth of S. aureus in milk (0.83-0.89 log scale) compared to the control. Co-delivered encapsulated flavonoids are a promising alternative to chemical preservatives.

Baking Process Effects and Combined Cowpea Flour and Sorghum Bran on Functional Properties of Gluten-Free Cookies

Gluten-related disorders, including celiac disease and non-celiac gluten sensitivity, are growing worldwide. The only treatment for both disorders is a lifelong gluten-free diet. However, gluten-free foods are generally poorer in nutrients, less healthy, and have a high cost. Sorghum and cowpea are gluten-free grains with high levels of phenolic compounds (PC) and a low cost. Their phenolic profile is structurally different; thus, the blend of both can provide synergistic/complementary health benefits to the final product. This study analyzed the effect of baking process and the blend of cowpea flour (CP) and sorghum bran (SB) on the levels of PC, resistant starch (RS), neutral detergent fiber (NDF), and antioxidant capacity (AC) of gluten-free cookies. Eleven rice or cowpea cookie formulations were made with or without white sorghum bran (WSB) or black sorghum bran (BSB). Baking increased the extractability of PC, AC, and the NDF of almost all formulations. The PC and AC were, respectively, about twice and 3-5 times higher in cookies containing BSB compared to the others. There was a minor effect of WSB on the PC and AC. Although there were losses, the retention of RS of cookies after the baking process was between 49.8 and 92.7%. Sorghum bran has excellent potential for use as a functional ingredient in healthy food production. The combined CP and SB have great potential to improve the nutritional and functional properties of gluten-free products, especially the PC, RS, and NDF contents.