Effect of Cross-Section Differences and Drying Temperature on the Physicochemical, Functional and Antioxidant Properties of Giant Taro Flour

Effects of taro [Colocasia esculenta (L.) Schott] slices on nutritional quality, sensory quality, and shelf life of Chinese pickled and steamed pork belly

This study aimed to investigate the influence of different ratios of taro slices (TS) on the nutritional quality, sensory quality, and shelf life of Chinese pickled and steamed pork belly (CPSPB). The study examined various aspects of CPSPB, including its proximate components, fat oxidation, fatty acid composition, protein hydrolysis, oxidation reaction, and induction period (IP). Additionally, the sensory quality and texture analysis were compared simultaneously. The results showed that the addition of TS to CPSPB significantly improved water and lipid loss (p < 0.05), increased the unsaturated/saturated ratio of fatty acids, and reduced lipid and protein oxidation. Additionally, the incorporation of TS extended the IP and enhanced the shelf life of CPSPB. Particularly, the addition of a specific amount of TS (60%) to CPSPB resulted in the highest organoleptic quality. Therefore, these results emphasize the positive impact of TS on the overall quality of CPSPB, highlighting its potential to enhance the nutritional value, sensory attributes, and shelf life.

Effects of gradually increasing drying temperatures on energy aspects, fatty acids, chemical composition, and in vitro ruminal fermentation of acorn

Acorns are commonly used to meet energy, protein, and mineral needs of livestock in various parts of the world. However, since acorns have quite a high moisture content at harvest, they should be stored as dried to prevent loss of nutrients and spoilage throughout storage periods. The aim of this study is to determine the drying kinetics, color, energy aspects, crude protein, crude ash, crude oil, fatty acid composition, ADF, NDF, condensed tannin, and mineral composition properties of acorns dried at gradually increasing drying temperatures. Drying processes were carried out in an air-convective dryer at temperatures of 40, 60, 80, 100, and 120 °C. The Logistic model was identified as the best model for describing current drying conditions. Increasing drying temperatures reduced L* (lightness) values and increased thermal efficiency and effective moisture diffusion values. In terms of energy efficiency, the best outcomes were achieved at 80 °C and 120 °C drying temperatures. Drying temperatures had highly significant effects on nutritional traits of acorn samples. Increasing drying temperatures increased fiber content, gas-methane production, and energy values and reduced crude protein and oil contents. Some minerals decreased and some others increased with increasing drying temperatures. Increasing drying temperatures caused slight changes in fatty acid compositions. In terms of animal drying and feeding characteristics, it was determined that a drying temperature of 80 °C was ideal for acorn drying.

Effect of Parinari curatellifolia Peel Flour on the Nutritional, Physical and Antioxidant Properties of Biscuits

This study investigated the impact of Parinari curatellifolia peel flour on the nutritional, physical and antioxidant properties of formulated biscuits. Biscuits enriched with 5%, 10%, 15% and 20% of Parinari (P). curatellifolia peel flour were formulated and characterised. Thermal, physicochemical, polyphenolic compounds and antioxidant properties of flour and biscuits were determined. The incorporation of P. curatellifolia peel flour significantly increased (p < 0.05) thermal properties (onset, peak and conclusion temperatures) of flour. However, enthalpy of gelatinisation, viscosity and pH of flour samples decreased. Nutritional analysis revealed an increase in ash (0.74% to 2.23%) and crude fibre contents (0.39% to 2.95%) along with an increase of P. curatellifolia peel flour levels. Protein content and carbohydrates decreased while moisture content was insignificantly affected by the addition of P. curatellifolia peel flour. The L*, b* values and whiteness index of formulated biscuits decreased while parameter a* value (10.76 to 21.89) and yellowness index (69.84 to 102.71) decreased. Physical properties such as diameter (3.57 mm to 3.97 mm), spread ratio (2.67 to 3.45) and hardness (1188.13 g to 2432.60 g) increased with the inclusion levels of peel flour while weight and thickness decreased. The inclusion of P. curatellifolia improved the polyphenolic compounds and antioxidant activity of biscuits with values of total flavonoids content ranging from 0.028 to 0.104 mg CE/g, total phenolic content increasing from 20.01 mg to 48.51 mg GAE/g, ferric reducing antioxidant power (FRAP) increasing from 108.33 mg to 162.67 mg GAE/g and DPPH (2,2-diphenyl-1-picrylhydrazyl) from 48.70% to 94.72%. These results lead to the recommendation of the utilisation of P. curatellifolia peel flour to enhance the nutritional value, polyphenolic compounds and antioxidant activity of bakery products such as biscuits.

Antioxidant property, anti-inflammatory and analgesic effects of aqueous extracts of two onion bulbs varieties (Allium cepa L.)

Background

oxidative stress and inflammation remain the main health problems often linked to degenerative diseases. The aim of this study was to evaluate antioxidant, analgesic and anti-inflammatory properties of onion growth in Cameroon.

Methods

Aqueous extracts were produced from two varieties of onion (Violet of galmi; Goudami) and were quantified for their polyphenols content. Concentrations of extracts (0.1, 0.5, 1, 1.5 mg/mL) were also prepared, their in vitro antioxidant properties evaluated by using standard methods. Anti-inflammatory effect of onion extracts was assessed by applying carrageenan sub plantar test to Wistar rats, but acetic acid test was used to study analgesic effect.

Results

The polyphenols content and antioxidant activities of onion extracts changed significantly (p < 0.05) with variety and increased (p < 0.05) with concentration. Total phenolic (range 58.03–67.43%), Total Reducing power (range 0.27–0.94%), DPPH radical scavenging (range 37.33–202.08%) were higher in Violet of galmi extracts, while Ferrous ion chelating power (range 23.15–97.42%) was higher in Goudami extract. The two varieties of onion extracts reduce (p < 0.05) rat paw edema in a dose dependent manner compared with negative control group. Violet of Galmi variety (1.5 mg/kg) reaches 100% of inhibition after 2 h whereas the Goudami variety (1.5 mg/kg) reaches 100% of inhibition after 3 h. In terms of analgesic activity, aqueous extract of the two varieties of onion exhibited analgesic effect characterized by reduction in writhes. Analgesic activity increased significantly (p < 0.05) with concentration of onion but Violet of galmi extracts has also shown more efficacy than Goudami extracts.

Conclusion

The present findings suggest that aqueous extract of violet of galmi and Goudami bulb onions have antioxidant activity and protective effects against inflammation and pain.

Evaluation of the Content of Polyphenols, Antioxidant Activity and Physicochemical Properties of Tortillas Added with Bambara Groundnut Flour

The effect of substituting maize (masa) flour with Bambara groundnut flour in tortillas production was investigated. Thermal, antioxidant, physicochemical properties, degree of puffing and rollability of flour and tortillas were determined. Tortillas were produced from maize and Bambara Groundnut (BGN) flours at the ratio of 100:0, 95:5, 90:10, 85:15 and 80:20, respectively. Compositing maize with BGN flour showed an improvement on the proximate composition of maize flour and tortillas; however, carbohydrate content of tortillas significantly decreased with the addition of BGN in blends from 77.07 to 55.22. The temperatures of gelatinisation such as onset temperature (T_o) of flour blends increased from 57.50 to 71.95 °C, peak temperature (T_p) from 74.94 to 76.74 °C and the end temperature (T_e) from 81.72 to 91.58 °C. Composite flours and tortillas had higher values of polyphenolic compounds and antioxidant activities than the control sample. Textural properties of control tortillas were higher than that of composite tortillas. Increase in the levels of BGN flour improved the weight and thickness of tortillas. However, diameter and spread ratio decreased. Degree of puffing and rollability of tortillas increased with the incorporation levels of BGN flour.

Effects of Air-Impingement Jet Drying on Drying Kinetics, Nutrient Retention and Rehydration Characteristics of Onion (Allium cepa) Slices

This study is designed to investigate drying kinetics, nutrient retention and rehydration ratio of onion slices under air-impingement jet drying (AIJD) with different drying temperatures (40, 50 and 60°C), air velocities (11, 12 and 13 m/s), and the distance between jet nozzles and material box (0, 40 and 80 mm). Additionally, the influence of AIJD and hot air drying (HAD) on drying efficiency and product quality of onion slices was comparatively investigated. It was found that the moisture effective diffusivity of onion slices under AIJD ranged from 3.51 × 10−10 to 5.51 × 10−10 m2/s, and the activation energy (E a) of onion determined from Arrhenius equation was 14.73 kJ/mol, and ascorbic acid content (AAC), total phenolic content (TPC) and DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (DSA) significantly decreased in the dried onions compared to that in fresh onion. In addition, the results suggest that the Modified Page model provides the best fit for AIJD curves. Furthermore, AIJD product is better than HAD both in decreasing drying time and enhancing drying rate, AAC, TPC, DSA and rehydration ratio. Accordingly, the AIJD method has advantages in drying time and quality of products, indicating that this technology can be widely applied to food drying process.

Mucilage chemical profile and antioxidant properties of giant swamp taro tubers

The yellow (YP) and white (WP) sections of giant swamp taro (GST) contain 40.0 g/kg and 51.5 g/kg (dry wt) respectively of pure mucilage made up of D-glucose (44.95-78.85 %), D-galactose (8.70-25.35 %), D-mannose (3.20-10.45 %), D-arabinose (2.45-5.20 %) and small amounts of glucuronic acid and rhamnose. Arabinogalactan-proteins (5.30-8.83 g/kg) contain mainly arabinose and galactose (in a 1:1 proportion) and also significant amounts of rhamnose, xylose, glucuronic acid and mannose. Antioxidant activity of YP was higher than those of WP while chelating ability and reducing power increased with mucilages content. Generally YP and WP showed better reducing power (1.06 ± 0.35 at 5 mg/mL) than ascorbic acid (0.89 ± 0.22). WP and YP chelated ferrous ions by 20.0-76.0 % and 16.4-71.0 % respectively. Effective concentrations (EC50) of mucilages (WP 1.28 ± 0.05 mg/mL; YP 1.42 ± 0.04 mg/mL) were lower than those of citric acid (1.58 ± 0.04 mg/mL). Generally mucilage from the WP and YP sections are excellent sources of chelating agents.