The effect of process parameters on oil expression efficiency from freshly dried coconut gratings was investigated. The range of parameters investigated were: pressing time, 4 and 8 min; particle size, fine (0.6 - 1.18 mm) and coarse (1.18 - 2.36 mm); pressure, 3-33 MPa; moisture content, 3%, 7%, 11% and 15%; and temperature, 30 degrees C, 60 degrees C and 90 degrees C. Results showed that 8 min of pressing and finer particles both led to significantly (P < 0.05) higher oil expression efficiency. The pressure increase within the range 3-13 MPa led to significantly higher oil yields, with yields leveling off thereafter. The effect of pressure increase was highly associated with the moisture content of the gratings, and the optimum moisture content under low-pressure pressing was found to be 11%. A pressing temperature of 60 degrees C led to higher oil expression efficiency, whereas a further increase of temperature to 90 degrees C did not lead to a significant increase in oil yield.

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Soymilk is a good replacement of cow's milk in places where cow's milk is not available in sufficient quantity. Acceptability of this soymilk as cow's milk substitute is greatly influenced by flavour. Blending with common fruits like bananas and pineapples and other low cost ingredients as flavouring agents such as lemon grass, honey or sugar to suppress the unpleasant flavour in soybean-based products has not been fully investigated in Tanzania. The objective of this study was to assess the effect of blending soymilk with pineapple, banana, lemongrass, honey or sugar on acceptability of the resulting blends. Sensory evaluation involving 25 semi-trained panelists in two different studies employed a five point hedonic scale (1=Dislike extremely, 5=Like extremely and 3=Neither like nor dislike) to assess the extent of liking of the blends. The attributes investigated were colour, taste, smell, appearance and general acceptability. Pineapple-flavoured blends were more acceptable than the banana flavoured ones. Banana-flavoured blends resulted in phase separation that accounted for the relatively low acceptance. Soymilk from different soybean varieties also showed variation in acceptability. Regarding overall acceptability, with the exception of the banana-flavoured milk samples that were unacceptable or marginally acceptable, soymilk samples from Kaleya, Duicker and Sable varieties were more acceptable than the rest. With reference to lemon grass, honey and sugar, mean scores of appearance of soymilk ranged between 3.5 and 3.8 with cow's milk the highest (mean score 4.7). Colour ranged from 3.0 to 4.0 for the products (cow's milk 4.9). The mean score range for odour was 2.8 to 4.2 (cow's milk 4.2), taste 3.2 to 4.6 (cow's milk 4.3) and overall acceptability 3.0 to 3.8 (cow's milk 4.6). Cow's milk was significantly (p<0.05) superior in all parameters studied with the exception of taste, where lemon grass-flavoured the soymilk more (mean 4.6) than cow's milk (mean 4.3) although there was no significant difference (p>0.05) between the two products. Common fruits like banana and pineapple as well as lemon grass and honey could be used in promoting acceptability of soymilk where cow's milk is either unaffordable or unavailable or there is lactose intolerance in the community. Increased use of these beany flavour suppressants and more investigations to expose other promising flavouring agents are recommended.

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