Elucidation of chickpea hydration, effect of soaking temperature, and extent of germination on characteristics of malted flour

Effect of malting on physicochemical, antioxidant, and microstructural properties of finger millet (Eleusine coracana) flours

Finger millet (Eleusine coracana L. Gaertn.) is a gluten-free crop with a high amount of fiber, calcium and iron, outstanding malting qualities and a low glycemic index. The study aimed to determine the physicochemical, functional, antioxidant and microstructural properties of malted finger millet (light and dark brown) flours. The two varieties of finger millet grains were germinated for 0, 24, 48 and 72 h and kilned for 8 h. The lightness (L*) values of malted finger millet flours significantly increased, with light brown having the highest L* value of 76.62. The hue angle and total color differences (ΔE) of the malted finger millet flours increased significantly (p ≤ .05.), and values ranged from 63.43° to 71.20° (light brown) and 2.12° to 4.32° (dark brown), respectively. The moisture, ash, fiber, protein, total phenolic, total flavonoids contents and DPPH activity of both malted finger millet flours significantly increased. On the contrary, the fat, carbohydrate, energy contents and FRAP activity significantly decreased with each malting period of both finger millet flours. Both malted finger millet flours' solubility index, water and oil absorption capacity increased significantly while the packed and loose bulk density decreased. Malting had no significant effect on the viscosity of the cold paste; however, a significant decrease in the viscosity of the cooked paste in both finger millet flours was observed, with values ranging from 285 to 424.00 cP (light brown) and 271.33 to 418.00 cP (dark brown), respectively. Malting resulted in changes in the thermal properties of finger millet flours with an increase in the onset, peak and conclusion temperatures. Fourier-Transform Infrared Spectra showed that malting slightly changed the peaks of both finger millet flours. Scanning electron microscopy showed that malting altered the microstructural characteristics of finger millet flours. The results showed that malted finger millet flours are promising raw materials for gluten-free bakery products.

Germinated Bambara groundnut (Vigna subterranea) flour as an ingredient in wheat bread: Physicochemical, nutritional, and sensory properties of bread

Wheat flour (WF) was substituted with germinated Bambara groundnut (Vigna subterranea) flour (GBF) at different proportions (5%, 10%, 15%, 20%, 25%, and 30%) and used in the preparation of bread. The dough mixing, pasting, and gelatinization properties of the blends were evaluated as well as the nutritional quality, in vitro starch digestibility, phytochemical constituents, antioxidant potential, color, texture, and sensory properties of breads. All the wheat dough containing GBF had higher water absorption capacity, gelatinization temperatures, dough development time, low peak, and setback viscosities. The composite breads had significantly higher dietary fiber, minerals, protein digestibility, corrected amino acid scores, resistant starch, slowly digestible starch, total phenolics, total flavonoids, and antioxidant activities and caused significant reduction in rapidly digestible starch content. The addition of up to 15% GBF had no significant impact on the specific volume of wheat bread. Substitution of WF with GBF influenced color and texture properties of bread. Wheat bread supplemented with 20% GBF had significantly higher scores in taste, aroma, and overall acceptability. This study demonstrated the potential of GBF as a functional ingredient in bread making. PRACTICAL APPLICATION: This study provides a suitable possibility of partial substitution of wheat flour with germinated Bambara groundnut, to develop functional and acceptable bread. The dough mixing and pasting results in this study would add to knowledge on the dough handling characteristics as there is limited information regarding the mixing properties of wheat dough with germinated Bambara groundnut.

Effect of germination pretreatment on the physicochemical properties and lipid concomitants of flaxseed oil

This study investigated the effects of germination pretreatment on the physicochemical properties, lipid concomitants, and antioxidant activity of flaxseed oil in three varieties. The results indicated that the oil content of flaxseed decreased by 2.29-7.40% during the 5 days germination period. Germinated flaxseed oil showed a significantly higher acid value and lower peroxide value. The unsaturated fatty acid content was slightly increased by germination. Germination pretreatment resulted in significant increases in the α-tocopherol, stigmasterol, pigments, total phenols, and antioxidant activity. As germination time progressed to 5 days, α-tocopherol which was traditionally recognized as having the highest antioxidant activity form of vitamin E in humans increased from 3.07-6.82 mg kg^-1 to 258.11-389.78 mg kg^-1. Germinated oil had 1.63 to 2.05 times higher stigmasterol content than non-germinated oil. The chlorophyll and carotenoid also increased exponentially. The total phenol content of flaxseed oil increased from 64.29-75.85 mg kg^-1 to 236.30-297.78 mg kg^-1. Germinated flaxseed oil showed important antioxidant activity. Compared with other varieties during germination, the oil from Gansu showed a higher level of α-linolenic acid, tocopherols, and carotenoid, and a maximum increase level of tocopherols and phytosterols. The comprehensive evaluation of germination time by correlation and principal component analysis showed that when germination time exceeded 2 days, the lipid concomitants and antioxidant capacity of flaxseed oil were significantly improved.