The changes in physico-chemical properties of yoghurt containing cress seed mucilage (CM) compared with yoghurt containing guar gum (GG) or plain yoghurt during storage at 5 ± 2°C for 15 days were evaluated. CM was prepared and added to standardized buffalo's milk ($3.2% fat and $15.0% TS) at rate of 0.025%, 0.05% and 0.10% but GG was added at the rate of 0.025% and 0.05% to create 5 treatments. The latter batch had no CM or GG, serve as a control (C). No significant changes in pH values and proteolysis (SN/TN ratio) of all yoghurt samples throughout the storage period were observed. CM containing yoghurts showed adverse effect on the concentration of acetaldehyde and diacetyl until day 10 and day 15, respectively compared with C and that containing 0.025% GG. Yoghurt samples containing different levels from CM or 0.025% GG exhibited lower in wheying-off and whey syneresis compared with C. No significant changes in the firmness of the yoghurt containing 0.025% and 0.05% CM or 0.025% GG were found throughout the storage period, while yoghurt containing 0.05% GG exhibited lower firmness compared with other yoghurt samples. Apparent viscosity of yoghurt containing GG or CM was higher than that of C until day 10. However, yoghurt containing 0.025% and 0.05% CM or 0.05% GG showed continued increase in apparent viscosity until day 10 while for yoghurt containing 0.10% CM, the increase was observed until day 5 and decline thereafter. ª 2015 Production and hosting by Elsevier B.V. on behalf of Faculty of Agriculture, Ain Shams University.

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Background. Ice cream is a product rich in calories, due to its high carbohydrate, protein, and fat contents, but poor in antioxidants, fibers, and vitamins. The golden berry is a fruit rich in phenols, fibers, minerals, and vitamins. This study was carried out to improve the functional properties of ice cream by incorporating concentrated golden berry juice (CGBJ) in its formulation. Materials and methods. The fresh juice of mature golden berries was concentrated (41.01% total solids) and added at the level of 0, 3, 6 and 10% respectively to the ice cream formulations. Results. The CGBJ contained a high level of total soluble solids (37.69 Brix), total phenolic compounds (21.31 mg TAE/100 g) and ascorbic acid (97.15 mg/100 g). It was also rich in some elements, including K (1522.8 mg/100 g), Fe (9.49 mg/100 g) and Zn (3.05 mg/100 g). The antioxidant activity of CGBJ measured using DPPH and ABTS methods were 440.4 and 420.4 μg TE/g, respectively. The acidity, surface tension, and apparent viscosity of the ice cream mixture increased, but the pH value and freezing point decreased as the level of CGBJ in the formulation increased. The addition of 6% CGBJ improved both the whipping ability and overrun of the ice cream with more acceptability and quality. Inversely, ice cream containing 10% CGBJ had the lowest overrun and melting properties, while also having the highest fat destabilization compared to any other ice cream. Conclusion. The physical and sensory properties of ice cream can be improved by adding CGBJ up to 6%. In addition, CGBJ can be used to produce a functional ice cream rich in bioactive components including antioxidants, vitamins, and some elements.

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The effect of using ethanol precipitated cress seed (CSM) and flaxseed (FSM) mucilages in ice cream manufacture compared with commercial Guar Gum (GG) was studied. Ten treatments of ice cream mixes consisted of 10.0% milk fat, 11.5% MSNF and 15.0% sucrose were prepared. The CSM, FSM and GG were added separately at the rates of 0.025, 0.05 and 0.10% (w/w) to create 9 treatments. The latter batch had no polysaccharides' serve as a control. The results showed that the using of CSM and FSM had no significant effect on pH value, acidity content and surface tension of ice cream mix compared with GG or control mix. Protein load was the highest in ice cream mix containing 0.025% GG and CSM, however, protein load decreased, as GG or CSM concentration increased. The ice cream mix containing 0.025% GG exhibited lowest viscosity, while that containing 0.05% GG exhibited highest viscosity compared with those containing other polysaccharides at the same portion. As addition rate of 0.1%, mix containing FSM was higher than that containing CSM, however, mix containing GG separated into two layers. The overrun was the highest in the frozen ice cream containing 0.025% FSM or CSM but the lowest in that containing 0.05% GG. The decrease in hardness of ice cream was related to the increase in mix viscosity more than the increase in overrun percentage. Finally, addition of 0.025% FSM, CSM or commercial GG was the best percentage to improve the physical and sensorial properties of ice cream.