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Crude extracts of Ranunculus asiaticus anthocyanin pigment were obtained using several solvents, and their stability to light and heat with varying pH and water activity (a w ) levels was studied. Yield of the crude pigments was approximately 48 mg g )1 petals as cyanidin-3-glucoside equivalents in HCl: methanol (1:99, v:v). The pigment was moderately stable to heating at 50°C and 80°C, with its degradation curve showing two linear stages with heating time. The heat stability of the pigment extract in a buffer system was reduced by increasing the pH and water activity of the heating medium, and by inclusion of sugar. Light had a highly significant (P £ 0.01) negative effect on the pigment stability during storage especially in the presence of sugar. The pigment used in the colouring of a carbonated beverage was more stable during long time storage at 4°C than at room temperature. The ethanolic pigment extract could be used successfully in the colouring of gelatine desserts and carbonated beverages, as well as yogurt.

Cereal Chem. 82(5):499-503Two types of flat bread (thin and thick) were produced from straightgrade flour by the traditional straight dough (SD) and sponge and dough (SPD) methods using 50 and 60% sponges. Quality of the resulting bread was evaluated with respect to specific volume, crumb distribution between layers, moisture content, overall sensory quality, and rate of staling. The results showed that the method of production has a significant effect (P < 0.05) on the specific volume of the crumb-rich thick flat bread but not on the almost crumb-free thin type. The study showed that breads produced with the SPD method were superior to those produced by the SD method with respect to their overall quality and resistance to staling, and that using 50% sponge gave bread with superior overall sensory quality to that obtained using 60% sponge. The results indicate that the Structograph can be used to follow the staling of these breads. Nonetheless, using the SPD method has some drawbacks, mainly longer fermentation time, and more space, mixing, and labor requirements that are expected to limit its use in commercial production of flat bread types.

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Nanocapsules of alpha‐linolenic acid (α‐LA) were prepared by a modified emulsion diffusion technique with encapsulation efficiency of 93%. Polylactic acid (PLA) was used as the encapsulating polymer with acetone and ethyl acetate as organic solvents, and Tween 20, gelatin and Pluronic‐F68 in water as stabilizers. Two ratios of organic to aqueous phases were used with each solvent and stabilizer. Nanocapsule dispersions with a particle size less than 100 nm and a zeta potential as high as 33 mV were obtained as verified by scanning electron microscopy and the dynamic light scattering technique respectively. Both particle size and zeta potential were influenced by such preparation conditions as the type of stabilizer, type of organic solvent and the organic to aqueous phase ratio. Acetone was superior to ethyl acetate, and Tween 20 was superior to each of Pluronic‐F68 and gelatin in obtaining smaller, less aggregated nanocapsules. An organic to aqueous phase ratio of 1:5 was shown to be more suitable for the formation of smaller nanocapsules, particularly when acetone was used as the organic solvent.