贮藏时间和温度对生食粉品质影响的初探

本文研究了贮藏温度和时间对生食粉产品品质的影响,优化了最适贮藏条件。将生食粉分别置于20℃、40℃、60℃温度条件下,测定60d 内不同贮藏时间的感官指标、菌落总数、乳酸菌和大肠杆菌含量。结果表明,生食粉感官质量随着贮藏时间的延长而下降,菌落总数、乳酸菌和大肠杆菌含量在20℃、40℃条件下随贮藏时间的延长而增长,60℃条件下随贮藏时间的延长而下降。产品在20℃条件下贮藏可保持较好感官、卫生质量。

Biological Value of Maggot Meal as a Replacement for Fishmeal in the Diets of African Giant Snail （Achatina spp.） Hatchings

Poverty, inadequate dietary intake, and diseases are the major causes of malnutrition in Nigeria. Averagely, Nigerians consume about 5.5 g of animal protein per day which is low compared to the minimum of 30 g per person per day as recommended by Food and Agricultural Organization. The concept of household food security ensures that adequate food can be obtained, either through home production or purchases. Snail production is one of the means through which these ills could be eliminated. Protein deficiency that is endemic in developing nations can be reduced through the domestication of micro-livestock like snail which is rich in protein and iron. Sixty Achatina achatina hatchlings were used in a 90 days feeding trial. The hatchlings were assigned to four treatments in a Completely Randomized Design with three replicates each. Maggot meal was incorporated at the levels of 0.6, 1.4, and 2 kg per 100 kg of feed in treatments 2, 3 and 4, respectively. Treatment 1 had no maggot meal and served as the control. Results showed that snail weight, shell length and shell width increased with increase in the levels of maggot meal. Hatchlings on T3 and T4 had statistically similar values （P 〉 0.01） which were significantly （P 〈 0.01） higher than values obtained for hatchlings on T1 and T2 .Weight gain and feed conversion values of hatchlings on T3 and T4 were also significantly higher than values observed for hatchlings on T1 and T2. Therefore, maggot meal could effectively replace fishmeal in the diet of African giant snail hatchlings.

Modified Predator-Prey Model for Mealybug Population with Biological Control

Mealybugs are a major pest for many crops （such as the vegetable Cassava, in Thailand）. An environmentally-friendly bio-control method is implemented using an introduced predator （green lacewings） of the mealybugs to mitigate plant damage. This is analyzed so as to devise and determine an optimal strategy for control of the mealybug population. A predator-prey model has been proposed and analyzed to study the effect of the biological control of the spread of the mealybugs in the plant field. The behaviour of the system in terms of stability, phase space and bifurcation diagrams are considered. The results obtained from different numbers of predators being released are compared. In particular we obtain thresholds of introduced-predator level above which the prey is driven to extinction. Future models will include age-structured multi-compartments for both the prey and predator populations.

Nutrient Composition of Cereal （Maize）, Legume （Soybean） and Fruit （Banana） as a Complementary Food for Older Infants and Their Sensory Assessment

Four complementary foods were prepared from local foodstuffs which are maize （Zea mays）, soyabean （Glycine max） and banana （Musa acuminate colla）. Four complementary samples were produced from the proportion of maize/soyabean/banana composite flours as 60%： 30%： 10% （B）, 60%： 25%： 15% （C）, 60%： 20%： 20% （D）, 50%： 30%： 20% （E） and Nestle Cerelac was the control sample （A）. The formulated diets were subjected to nutritional analysis-along with a commonly used proprietary infant cereal （Nestle Cerelac） as control. Standard chemical methods were used to determine the proximate nutrient composition, some micronutrients and anti-nutritional factors. The samples produced have increased nutrients of fibre that enhances digestibility （2.07%-3.11%）, protein and ash contents. The supplementation of up to 20% soybean flour and banana flour recorded the best results in terms of proximate and mineral compositions and compared favourably with the control sample, in terms of sensory evaluation using hedonic method, sample A was most accepted but did not differ significantly from sample D. Therefore, nutritious and acceptable complementary food can be produced from fermented maize, soybean and banana flours. Results of molar ratios of some minerals and anti-nutritional factors in the compounded diets suggest that the anti-nutrients will not pose any serious problem in the usage of the complementary diets. The cost of producing the formulated diets is about N50-N100 （50 cents） per gram cheaper than cerelac. The study has therefore, revealed that with proper selection of local foodstuff, it is possible to prepare nutritious complementary diets that would be acceptable, readily available, affordable and nutritionally adequate.

Cooking Quality Parameters of Rice Cultivars Grown in Spain

The quality office is complex and made up of many components such as nutritional quality, appearance, cooking quality and eating quality. The cultivar is one of the main factors that could affect to the grain quality office. The aim of this work was to analyze and compare the cooking quality parameters of six different japonica varieties of rice grown in Spain （Senia, Gleva, Bahia, Maratelli, Guadiamar and Bomba）. This work focused on the study of the cooking quality of rice, because it is one of the most important factors related to grain quality in Spain. It was evaluated using five characteristics： amylose content, gel consistency, degree of spreading, gelatinization temperature and pasting parameters. The amylose content ranged from 11.60% to 21.46%, with the Gleva cultivar having the lowest amylose content and with Bomba having the highest. The gel consistency varied between 5.44 cm and 9.81 cm. Regarding the alkali test, the Maratelli cultivar had the highest dispersion and transparency. Maratelli had the lowest gelatinization temperature （61.67±0.08 ℃）, and Senia had the highest gelatinization temperature （67.05±0.02 ℃）. Finally, the pasting parameters showed significant differences among cultivars with different viscosities.

FUNCTIONAL RESPONSE AND PLANT PREFERENCE OF NEPHASPIS OCULATUS (COLEOPTERA: COCCINELLIDAE), PREYING ON BEMISIA ARGENTIFOLII (HOMOPTERA: ALEYRODIDAE) IN THE LABORATORY

The predatory behavior and functional response of all larval stages and adults of Nephaspis oculatus (Blatchley), a predacious coccinellid, on various egg densities of Bemisia argentifolii Bellows & Perring, and prey preference of adult N. oculatus, were studied in the laboratory. Daily consumption of eggs of B. argentifolii by N. oculatus was evaluated at six different densities to obtain functional response curves for all active stages of the coccinellid. Bemisia argentifolii eggs were offered to N. oculatus on collard leaf disks in Petri dish arenas over a 24\|h period at 26 7 2℃ and a photoperiod of 14∶10 (L∶D) h. Linear relationships were observed between percentage prey consumed and prey density, with r 2 values between 0 82-0 99 for all stages except for the fourth instar that had a smaller r 2 value (0 64). Functional response curves of prey consumption by N. oculatus against density of B. argentifolii eggs fitted the type II model of Holling's disc equation for all larval stages and both the male and female adults. Adult females consumed more prey than adult males. The maximum theoretical number of prey consumed per day increased with larval development. The fourth instar was the most effective larval predator, followed by the third instar, the second instar, and finally, the first instar. Based on the functional response parameters, a maximum of 321, 312, 237, 229, 73, and 34 B. argentifolii eggs could be attacked by an adult female, a fourth instar, an adult male, a third instar, a second instar, and a first instar of N. oculatus, respectively. Nephaspis oculatus adults strongly preferred collard to tomato, soybean, eggplant or sweetpotato for oviposition and foraging. Nephaspis oculatus did not deposit any eggs on soybean and tomato.