Journal of Chemistry and Nutritional Biochemistry

Relationship between pH and antioxidant capacity of selected locally available vegetables

2024-12-07T23:57:27+00:00

In recent times, there have been controversies on the consumption of alkaline foods; with some authors suggesting that consistent consumption of acidic foods may lead to long-term health challenges, while consumption of alkaline foods will support health and help the body to remove the stress of an acidic lifestyle. Fruits and vegetables have been proposed to be associated with a greater degree of alkalinity. Thus, there is a need to determine the antioxidant capacities of selected vegetables with a particular focus on understanding how their pH influences antioxidant activity. This study evaluated 15 locally available vegetables: Fluted pumpkin leaves (Ugwu), Jute mallow (Ewedu), Bitter leaf, African basil (Scent leaf), Amaranthus, Cabbage, Lettuce, Okro, Cucumber, Cayenne pepper (Sombo), Habanero pepper (Rodo), Bell pepper (Tatase), Tomato, Carrot and Spring onions. The pH of the fresh and freeze-dried samples, Phytochemical analysis (Total phenolics and Ascorbic acid content) and Antioxidant Analysis-1, 1-diphenyl-2- picryl-hydrazil (DPPH) radical scavenging activity, Ferric reducing antioxidant power (FRAP) assay, Nitric Oxide (NO) scavenging activity and Total antioxidant activity (TAC)-were determined. Correlation analysis was done to establish relationships between pH, phytochemical constituents and antioxidant capacities of the selected vegetables. Results revealed that most of the fresh and freeze-dried vegetables had pH less than or greater than 7 respectively. The vegetables with higher concentrations of phytochemicals-ascorbic acid and total phenolic- had higher antioxidant capacities. While there was no significant correlation between pH and DPPH IC₅₀ there was a significant negative correlation between pH of freeze-dried samples and NO IC₅₀. Additionally, the pH of both fresh and freeze-dried vegetables was significantly negatively correlated with the TAC. This indicated that as the pH of the vegetables increased their antioxidant capacity reduced. Thus, the antioxidant potentials of these vegetables increased with increasing acidity which is contrary to popular belief.

Determination of the Proximate Composition and Organoleptic Properties of Milk Produced from Tiger Nut

2025-02-19T06:38:25+00:00

Tiger nut milk is a nutritious super food with various health benefits, including improved digestion, weight management, and better skin health. This study aimed to determine the proximate composition and organoleptic properties of tiger nut milk. The milk was prepared using conventional methods and evaluated by ten panelists over three days for aroma, color, taste, sweetness, and texture using a 9-point hedonic scale. The most acceptable sample contained 5g of ginger, while the least acceptable contained 7g of clove. Proximate analysis showed the milk had 67.38% water, 20.42% total solids, 1.07% ash, 3.25% protein, 6.06% fat, 0.48% fiber, 0.93% carbohydrate, and a pH of 5.32. The study included three treatments with varying preservatives (clove, ginger, and a combination of both) at different concentrations (3, 5, and 7g/L), with a control sample. Results showed a decrease in bacterial population as the pH became more acidic. The highest pH (4.9) was observed in the 7g clove treatment, while the lowest pH (3.5) occurred in the 7g ginger treatment. Treatment D (7g clove and ginger) had the lowest bacterial count. The tiger nut milk's proximate composition and sensory qualities were acceptable, and it remained stable for over 48 hours at ambient temperature.

Utilization of shrimp waste powder as a functional ingredient in fortifying ready-to-eat foods

2024-12-21T22:12:35+00:00

Shrimp waste, a byproduct of seafood processing, is rich in nutrients and bioactive compounds, making it a promising ingredient for sustainable food fortification. This study evaluated the potential of shrimp waste powder (SWP) as a functional ingredient in ready-to-eat shrimp soup and fish fingers. SWP was processed by drying at 60°C for 24 h, grinding, and storing at 4°C ± 1°C. Its chemical composition was analyzed, revealing 42.48% protein, 11.50% fat, 23.6% ash, and a pH of 7.1. SWP was incorporated into food products at levels of 5%, 10%, and 15%. Chemical, physical, microbiological, and sensory analyses were conducted on all samples. Results showed that the 15% SWP fortification in shrimp soup provided the best overall nutritional and sensory properties. Similarly, for fish fingers, 15% SWP fortification level yielded optimal flavor, texture, and microbiological safety. The study confirms that shrimp waste powder can effectively enhance the nutritional value of food products without compromising sensory or safety qualities, offering a sustainable method for utilizing shrimp waste in food production.