The palm beetles, Oryctes rhinoceros L are pests of palm trees in the tropics and are also very important as edible insects. This study was conducted to investigate the nutrient composition, mineral salt contents, functional properties and anti-nutrient factors of the developmental stages (i.e. larvae, pupae and adults) of Oryctes rhinoceros beetles. The samples were oven-dried and blended into fine particles before being used for nutrient composition analyses using standard procedures. Analysis of mineral salts, functional composition and phytochemical (anti-nutrient) composition were also carried out, using standard procedures. The results obtained showed that protein content was highest in the adult (74.18±0.15%) while larva and pupa had 70.76±0.12% and 65.34±0.11% respectively. The ash content of the larva was the highest with a value of 8.29±0.01% while the pupa and the adult had 3.17±0.01% and 5.29±0.01% respectively. The pupa was highest in fat content (20.21±0.03%) while the larva had 7.47±0.01% and the adult had 9.55±0.01%. The moisture contents of the larva, pupa and adult are 1.04±0.02%, 4.76±0.02% and 4.53±0.03% respectively. The larva stage had the highest soluble proteins while the lowest protein solubility was observed in the pupa stage. In the larva stage, the highest protein solubility occurred in acidic medium while in the pupa and adult, it occurred in basic and neutral media respectively. Phosphorus was consistently highest in all the developmental stages. While Cu was not detected in any of the developmental stages, Magnesium was the highest minerals in the beetle with the values of 71.54±0.20mg/100g, 56.55±0.13mg/100g and 58.73±0.11mg/100g in the larva, pupa and adults respectively. Other mineral salts that were detected include Na, K, Ca, Fe, Zn, Mn and Cr. All the developmental stages of O. rhinoceros have good functional properties and thus can be used in baking industries. They all have high water absorption capacity, oil absorption capacity, foaming capacity, emulsion capacity and good least gelation concentrations. The anti-nutrient values of all the developmental stages are of negligible quantity that will pose no threat to life since the values fall within the tolerance values. Oryctes rhinoceros is a good source of nutrients and minerals which can be put to better use to accelerate the proper growth and development of man and livestock.
Chemical Composition of Some Selected Fruit Peels (Published)
Global fruit production has experienced a remarkable increase. In 2011, almost 640 million tonnes of fruits were gathered throughout the world. In some fruits, peels represent almost 30% of the total weight and are the primary by-product. This study aims to investigate the chemical composition of fruit peels of some selected fruits. Peels of eight fresh fruits (orange, watermelon, apple, pomegranate, pawpaw, banana, pineapple and mango) were removed and analyzed for their nutrients and anti-nutrients contents. The results showed that lipid, protein, ash, crude fiber and carbohydrates contents in fruit peels were respectively from 3.36 ± 0.37 to 12.61 ± 0.63%, from 2.80 ± 0.17 to 18.96 ± 0.92%, from 1.39 ± 0.14 to 12.45 ± 0.38%, from 11.81 ± 0.06 to 26.31 ± 0.01% and from 32.16 ± 1.22 to 63.80 ± 0.16%. The minerals composition of fruit peels was respectively from 8.30 ± 0.54 to 162.03 ± 7.54 mg/100g for calcium, 0.66 ± 0.06 to 6.84 ± 0.55 mg/100g for zinc, 9.22 ± 0.63 to 45.58 ± 2.37 mg/100g for iron and 0.52 ± 0.10 to 9.05 ± 0.34 mg/100g for manganese. Concerning anti-nutrients, oxalates, hydrogen cyanides, phytates and alkaloids levels in fruit peels were within the threshold value reported as safety limit. The phenolics content of fruit peels ranged from 0.91 ± 0.06 to 24.06 ± 0.89%. Due to the proven health benefits of phenolic compounds, peels of these fruits can be used as good ingredients in formulation of health benefits food products.
Mineral and Antinutrients of Fresh and Squeezed-Washed Bitter Leaf (Vernonia Amygdalina) As Affected By Traditional De-Bittering Methods (Published)
The effect of traditional de-bittering methods on the mineral and anti-nutrient components of fresh and squeezed-washed bitter leaf was studied. Palm oil, Potash, Salt and boiling process was used in the squeeze-washing at 3 pre-processing methods of squeeze-wash and periods of 3 to 8 minutes. The percentage retention and losses of mineral and anti-nutrients increased simultaneously during squeeze-washing. Copper, magnesium, calcium and anti-nutrient had retention of 55 to 100% for samples squeezed-washed with palm oil than the other squeeze- washed samples. This could be due to rigidity of the cells which did not allow much nutrients to leach into the squeezed leaf-water. Loss of minerals and anti-nutrients was observed to be influenced directly by the cause-and-effect of disintegration changes which usually leads to softening due to the severity of the squeeze-washing on the bitter leaf instead of cellular composition or level of minerals and anti-nutrients initially present. Palm oil should be used in the squeeze-washing of bitter leaf for better nutrient retention.
Effect of Processing On the Nutritional and Anti Nutritional Properties of Canavalia Plagiosperma Piper Seeds (Published)
The effect of heat processing on the nutritional and anti nutritional qualities of oblique -seeded jack bean (Canavalia plagiosperma piper) was studied. Raw seeds of Canavalia plagiosperma (Oblique seeded Jack bean) were autoclaved (at 1210C, 15lb for 25, 30 and 35 minutes) and cooked (at 1000C for 30, 40 and 50 minutes). The proximate composition and anti-nutrients of the processed and raw samples were determined. The proximate composition showed that moisture content of raw seed was 8.26%, 35 minutes autoclaving increased it to 8.53% while 50 minutes cooking increased it to 8. 84%. Autoclaving reduced protein content from 31.54% to 31.28% while cooking reduced it from 31.54% to 28.86%. The ash content was reduced from 3.17% to 2.95% by autoclaving and from 3.17% to 2.51% by cooking. Autoclaving showed increasing effect on fat and energy content,(0.82-9.23%) and (1635.66-1637.94 KJ/g) respectively. The fibre content of the raw seed was found to be 0.94%, which was reduced to 0.88% by autoclaving and 0.62% by cooking. Cooking significantly increased the carbohydrate content (47.36-52.15%). The processing treatments showed significant effect (P≤0.05) on each parameter. Six (6) anti-nutrients (Saponin: 2.45%, Phytic acid: 3.15%, Tannin: 1.02%, Oxalate: 1.48%, Phenol: 0.34%, Trypsin Inhibitor: 11.53Tu/g) were determined in the raw seed. The six processing treatments given to the seed showed a general reduction trend on these six anti-nutrients at different rates and levels. From the results in Table 3 and 4, autoclaving was the best processing method for phytic acid, and phenol while cooking was the best processing method for tannin, trypsin inhibitor, saponin and oxalate.
African oak is one of the underutilized legumes in Nigeria. Information on various parts of this legume is required to enhance its utilization in foods and food products. Feeding of fowls with the flour made from the aril cap of the seed showed no harmful effect on them. The flour was then analyzed for chemical properties. Proximate analysis showed that the cap was appreciable in protein (5.69%), fat (18.5%), carbohydrates (63.91%), and fibre (5.4%) but low in ash (1.5%). The value of each of the anti – nutrients analyzed was below the lethal level. Although the cap was found to be low in ash content, it had appreciable amounts of some essential elements. These are sodium (7.10±1.00), potassium (148.0±0.10), calcium (7.02±0.00), magnesium (109.12±1.02 ppm), phosphorus (11.20±1.10 ppm), and iron (0.25±0.02mg/g).The vitamin components of the cap determined were A (234.7±0.00µg/g), C (4.0±1.00mg/100g), E (1.1±0.02mg/100g) and the B – vitamins; B1, B2, B6 and B12 (2.0±1.01, 33.0±0.11, 4.3±1.00 and 4.8±0.10)mg/100g, showing good amounts of the vitamins. Due to high proximate, vitamins, minerals and insignificant anti – nutrient compositions of the aril cap of the African oak seed, it could be used in both human and animal foods. There is therefore a need for food industries and feed formulators to utilize the cap.