Nutrient composition, functional properties, digestibility and formulation of selected food products from breadfruits (Artocarpus Spp. and Treculia Africana)
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Date
2011-07-12
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Abstract
Breadfruits (Artocarpus altilis, Artocarpus camansi, Artocarpus heterophyllus and Treculia africana) which grow in Ghana have been used as food security crops. In order to expand their use a survey was carried out in selected regions of Ghana using structured questionnaires to solicit baseline information on indigenous knowledge and traditional uses of the breadfruits. Standard procedures were then used to assess the physicochemical properties of the breadfruit flours as well as their digestibility. The data on chemical composition were used to establish predictive relationships for predicting digestibility, dry matter intake, net energy for production as well as relative food value. Selected food products were then formulated using breadfruit flours as substitute. The results of the survey showed that Artocarpus altilis and A. camansi were used for food (95.4%) while T. africana was mainly used for medicinal purposes (59%) and cocoa agroforestry (50.9%). With respect to their nutritional composition, the protein content of the flours of the nut-derived species (A. heterophyllus, A. camansi and T. africana) ranged between 12.23% and 17.72% whereas the crude fiber content varied between
1.67% and 2.91%, the carbohydrate content was between 57.00% and 70.15%. Potassium was the predominant mineral ranging from 533.95mg/100g in T. africana to
1313.3mg/100g in A. camansi. Magnesium levels varied widely between A. camansi (10.18mg/100g) and T. africana (167.71mg/100g). T. africana had significantly higher (P<0.01) calcium content (65mg/100g) than both A. heterophyllus (65mg/100g) and A. camansi (93mg/100g). On the other hand, sodium content ranged between 37.5mg/100g in A. camansi and 54.0mg/100g in T. africana. Phosphorus content varied widely between 201.60mg/100g and 440.00mg/100g. The iron content was highest in A.
heterophyllus (9.38mg/100g) while A. camansi had the least (2.20mg/100g). The nut
flours had bulk densities ranging between 0.53 and 0.76g/cm3. The functional properties were water absorption capacity (1.25-3.67g/g), oil absorption capacity (0.5-2.50ml/g), solubility (8.01-11.29%) and swelling power (4.84-6.32). The flours had peak viscosities ranging between 21.00BU and 125.00BU and setback values ranging between 7.67 and
38.00BU. On the other hand, the pulp (A. altilis) flours had the following attributes: crude protein (3.80%), crude fibre (3.12%), carbohydrates (79.24%), K (673.50mg/100g), Na (69.00 mg/100g), Fe (3.91 mg/100g), Mg (90.63 mg/100g), P (140.00 mg/100g), Ca (60.83 mg/100g), bulk density (0.57 mg/100g); water and oil absorption capacities (3.67g/g and 1.50ml/g respectively), solubility (11.55%), and peak viscosity of 354.33BU. No significant differences (P>0.01) were found in the tannin contents (3.44mg/100g to 4.30 mg/100g) of the breadfruit species. Lignin content was highest in A. camansi (12.1%) compared to the least (3.54%; T. africana). T. africana had the highest Digestible Dry Matter (78.51%) whereas A. camansi had the least (70.21%). Dry Matter Intake was highest in A. altilis (2.65% per kg body weight) and lowest in T. africana (1.72%/kg body weight). T. africana having the highest Net Energy for Production (88.00 Mca/lb) was similar to A. heterophyllus (86.77 Mcal/lb) but higher than A. camansi. A. altilis had higher Relative Feed Value (156.48) compared to A. camansi (137.13), A. heterophyllus (126.18) and T. africana (104.88). The predictors for Digestible Dry Matter were Acid Detergent Lignin, lignin, hemicelluloses and Nuetral Detergent Fibre. Dry Matter Intake was dependent on carbohydrate, fat, Acid Detergent Fiber, hemicelluloses and Neutral Detergent Fiber contents. On the other hand Net Energy for Production was predictable from Acid Detergent Lignin, lignin and hemicelluloses while Relative Feed Value was dependent on the carbohydrate, fat and
Neutral Detergent Fibre content. Predictive equations were derived in this study. The
products formulated from the breadfruit flours were of acceptable quality in terms of colour, mouthfeel, aroma, taste and overall acceptability with levels of substitution being
20% for breakfast meal, shortcake and koose and 40% for tatale. The results showed that the breadfruit species had good physicochemical properties and digestibility and vindicate their use as stop-gap food. The flours could be suitable for food applications. Thus, increased use of these flours in food product applications would enhance and expand their use.
Description
A Thesis Submitted to the Department of Food Science and Technology in partial fulfillment of the requirement of the Doctor of Science (Ph.D.) Degree in Food Science and Technology, October, 2011