Food Processing

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Browsing Food Processing by Funder "National Research Fund"

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    Effects of optimizing fermentation time and stabilizers using response surface methodology on physicochemical properties of camel milk yoghurt
    (Elsevier B.V., 2024-08-07) Philip K. Marete, Alfred M. Mariga, Guyo Huka, Levi Musalia, Eunice Marete, Julius M. Mathara, Joshua M. Arimi
    The objective of this study was to produce camel milk yoghurt with desired qualities using optimized processing conditions (fermentation time) and ingredients (stabilizer and calcium chloride). The conditions were obtained through Response Surface Methodology (RSM) by lactic acid fermentation by inoculating the milk with Lactobacillus delbrueckii subsp. Bulgaricus (YF-L903, CHR Hansen, Denmark. The study also determined the effects of fermentation time and ingredients on the quality of yoghurt. Fermentation time ranged from 2 to 22 h while stabilizer (corn starch) and calcium chloride (salt) ranges were 1.65–3.34 and 0.061–1.23 % respectively. The quality was monitored hourly for a fermentation period of 2–22 h by determining pH, total titritable acidity (TTA) and viscosity. Results indicated that viscosity was influenced by fermentation time, stabilizer and calcium chloride. The viscosity was increased from 0.01 to 0.4 and 0.01 to 0.3 by fermentation time, 0.01 to 0.2 and 0.01 to 0.3 by stabilizer and 0.01 to 0.5 and 0.01 to 0.6 Pa s by calcium chloride. Whereas the combined effects of calcium chloride and stabilizer increased the viscosity of yoghurt to 0.94 Pa s. Prolonged fermentation time, led to an increase in TTA and a decrease in pH. The finding from this study indicated that the optimal conditions required to produce camel milk yoghurt with desired qualities are a fermentation time of 10 h using 2.33 and 0.60 % corn starch and calcium chloride respectively. Under these conditions the produced camel milk yoghurt quality properties were a pH of 4.07, 0.32 % TTA and a viscosity of 0.35 Pa s.
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    Physical Properties of Dry-Milled Maize Meals and Their Relationship with the Texture of Stiff and Thin Porridge
    (African Journal of Food Science, 2014-08-31) Onyango, Calvin
    Selected physical properties of white maize meal, obtained by different dry-milling techniques were evaluated and correlated to the texture of stiff and thin porridge. Sifted or par-cooked maize meals had finer particles than hammer-milled maize meals. Hammer-milled maize meals had lower water absorption indices (17-38%) and higher water solubility indices (WSI, 4-5%) than sifted (41-42 and 2-3%, respectively) or par-cooked (114 and 2%, respectively) maize meals. Sifted or par-cooked maize meals had lower breakdown viscosities (0-19 BU) and higher final viscosities (818-1925 BU) than hammer-milled maize meals (89-173 BU and 530-780 BU, respectively). Stiff porridge prepared from par-cooked maize meal (34% w/v), and thin porridge from dehulled and hammer-milled maize meal (10% w/v) had the firmest textures at 80.93 and 1.28 N, respectively. There was a negative correlation (P < 0.05, r = -1.00) between the WSI and total shearing force of stiff porridge prepared from par-cooked maize meal.