EUREKA: Life Sciences

Dietary supplement using cockroach meal: impact on growth indices and biochemical responses in hybrid catfish

2023-05-15T15:15:16+03:00

Globally the need to substitute fishmeal with other animal protein sources in the fish diet has gained more attention; which is occasioned by the increasing cost of fish. A 12-week trial was conducted to ascertain the growth indices and biochemical response of hybrid catfish (Clarias gariepinus(♀) and Heterobranchus bidorsalis (♂)) fed cockroach meal supplement. A total of 800 hybrid catfish were randomly distributed into four dietary treatments (Diet A- control feed), Diet B (50 % cockroach and 50 % fishmeal), Diet C (100 % cockroach meal) and Diet D (100 % fishmeal). Each treatment was replicated with 35 fish per experimental pond in a completely randomized design. Progressive weight gain was determined bi-weekly. At the end of the study period, fishes were randomly sacrificed for proximate compositions and plasma biochemical analyses (glucose, triglyceride, cholesterol, total protein, albumin) using standard protocols. The study revealed that growth parameters (Weight gain, Average weight gain, Protein efficiency ratio, Feed Conversion rate, Specific growth rate and Survival rate (SR) were influenced by the dietary treatments (p>0.05). The highest weight gain was recorded in Diet 1 (8847.73±292.65 g) > Diet 2 (7816.33±121.71 g)>Diet 3 (7811.67±566.08 g) >Diet 4 (7022.00±44.193 g). Similarly, the best feed conversion ratio was found in fish fed Diet A (10.12±0.01),>Diet B, C and D had the same values of 0.11 g respectively. There was no significant (p>0.05) difference in plasma biochemical indicators measured when compared to the control (Diet A). Thus, indicating that all the fish were healthy and had normal physiological activities. Cockroach meal can therefore, be used as a feed supplement without having any adverse effect on the growth and well-being of hybrid catfish fingerlings

Revealing the influence of temperature and moisture content on electrophysical parameters of raw apple materials

2023-05-15T15:15:16+03:00

Additional heating of fruit raw materials in the drying process by direct passage of alternating electric current makes it possible to intensify the dehydration process by 3–5 times.

The amount of added thermal energy during direct electric heating depends, first of all, on the value of the specific electrical resistance of the raw material. Therefore, the list of necessary properties of the material must necessarily include the specific electrical resistance of the raw material as an integral indicator.

During drying with additional direct electric heating, the concentration of dry soluble substances, which directly depends on the moisture content of the studied raw material, and its temperature change throughout the drying time. This indicates a change in specific electrical resistance during the dehydration process. It was determined that the initial resistivity of apples before drying at a temperature of 20 °C and a moisture content of 8 kg/kg is within 195–220 Ohm•m, which indicates the high conductivity of the material.

With a decrease in moisture content from 8 to 6 kg/kg, the specific electrical resistance of the raw material decreases by 25–30 % compared to the initial values. With a further decrease in moisture content below 6 kg/kg, the electrical resistivity of the raw material begins to gradually increase.

At the same time as the temperature rises, there is a significant decrease in specific electrical resistance. When heating raw materials from 25 to 55 °C, the value of specific resistance decreases by 10–13 times.

The equation of the dependence of the specific electrical resistance of apple raw material on its moisture content and temperature for the studied apple varieties was obtained.

The obtained results of the change in the value of the specific resistance provide the necessary data for the development of an energy-saving technological device for drying fruits and the selection of optimal processing conditions in compliance with quality indicators

Development of the recipe for cookies with pumpkin flour

2023-05-15T15:15:16+03:00

The object of research is the technology of enriching shortbread cookies with pumpkin flour. The problem of enriching shortbread cookies with pumpkin flour was solved.

In the studies, different replacement of wheat flour with pumpkin flour was studied according to the following scheme: 0 %, 5 %, 10 %, 15 %, 20 %. The formation of strength, the ratio of the mass to the volume of the cake, its volume to the mass, the degree of swelling and sensory evaluation of the cookies were studied. As a result, it was established that the addition of pumpkin flour to the shortbread cookie recipe had a significant (р≤0.05) effect on its quality indicators. The strength of cookies and the ratio of its mass to volume increased with the addition of pumpkin flour. The degree of swelling and the ratio of the volume of cookies to mass decreased compared to the version without pumpkin flour. The use of pumpkin flour significantly changed the sensory indicators of cookie quality. The smell of cookies decreased from 9.0 to 3.7 points. The taste of cookies – from 9.0 to 3.0 points. Using it in the recipe reduces the volume of cookies, which reduces the degree of swelling and the ratio of its mass to volume. In addition, pumpkin flour has a specific smell and taste, which negatively affects the sensory evaluation of cookies. Therefore, the higher its content in the recipe, the worse the quality of the cookies.

A distinctive feature of the obtained results is the use of 5 % pumpkin flour in the cookie technology. With this recipe, the strength is 1.45 kg, the degree of swelling is 1.70, the ratio of cookie mass to volume is 0.65, cookie volume to mass is 1.53. The color of the surface of the cookies is light brown, the color of the crumb is yellow, the pores are small, thin-walled, uniform, the consistency is crumbly. Smell is 8.3 points, taste – 9.0 points.

The developed recommendations can be used by enterprises of low productivity for the production of shortbread cookies

Improvement of the manufacturing method of semi-finished fruit and vegetables of a high degree of readiness

2023-05-15T15:15:16+03:00

The method of production of concentrated fruit and vegeTable semi-finished product based on apples, Jerusalem artichoke and quince has been improved. Selected components of plant raw materials are chosen due to the presence of such useful substances as pectins, vitamins, minerals, etc. The obtained semi-finished products of a high degree of readiness are semi-finished products with a natural nutrient composition. A feature of the proposed method is the use of low-temperature modes of concentration and drying of raw materials. For the developed method, the hardware set of the line with the use of advanced thermal equipment was selected. Chopped raw materials are blanched in a universal multifunctional device: apple and Jerusalem artichoke in a steam environment (103 °C and 108 °C) for 4 and 8 minutes. Quince is blanched under conditions of pre-exposure in a 0.1 % solution of citric acid in an aqueous medium at a temperature of 75...80 °C (4...8 min.).

Concentration to a pasty state takes place in the improved design of the rotary-film apparatus with a reduced processing time of 0.75...1.25 s to a DM content of 28...30 %. To obtain a powdery state, a cylindrical IR dryer was used for drying to the final moisture content at the level of 4...6 % DM. It is also possible to dry the extracts formed after wiping the raw materials to a final moisture content of 10...13 % DM in an IR dryer. The use of low-temperature regimes in the range of 45...60 ^oC helps to obtain high-quality semi-finished products with maximum preservation of the initial properties of raw materials. By means of organoleptic evaluation, the best experimental sample with the content of blend components was found: apple 40 %; Jerusalem artichoke 35 %; quince 25 %. Developed semi-finished products are additives or fillers in various food products to improve their nutritional value

Seasonal assessment of pupal habitat productivity of malaria vector: Anopheles gambiae s.l as influence by physico-chemical conditions at selected breeding habitats in Niger, Nigeria

2023-05-15T15:15:17+03:00

Malaria is the most significant protozoan disease in Africa and the principal vector-borne disease (VBD) in Nigeria, which is influenced by the quality of breeding habitats that are reflected through the stage preceding adult. Control of Anopheles gambiae s.l. populations through source reduction is still considered the most effective way of prevention and control, although it has proven unsustainable in Niger State. Physico-chemical cues were investigated. Samples were taken inside and outside 1m² cages weekly by dipping and emptying the cages from May 2019 to March 2020. The data subjected to analysis of variance (one and two-way Anova). The findings revealed the mean pupae abundance (MPA), were significantly higher in Large Water bodies (624.50±217.81), and followed by Gutters (436.00±184.2) and Swamps (285.50±125.06). The mean pupae productivity (MPP), followed the order of descending rate >GT (717.50±219.38) >LW (677.21±145.10) >SW (530.40±136.97). The result also showed that emptying technique (ET) was more sufficient and reliable than dipping technique (DT). The peak abundance and productivity of the pupal stage was June to August then declined in March,2020 both habitats. However, MPP differed significantly (p<0.05) from one another across the months in all the habitat types. The physical and chemical cues of the breeding sites, varied significantly, except in temperature, total hardness, biochemical oxygen demands, conductivity, and pH in all the habitats. This study revealed high utilization of physico-chemical properties and poses increased risk of malaria. Thus, emphasis on the vector management strategies should be given specially on gutters and large water bodies as breeding habitats of malaria vectors (MV), in Niger State

Urinary schistosomiasis: risk factors and symptoms among school adolescents in Kaduna State, Nigeria

2023-05-15T15:15:17+03:00

Improper waste disposal, unsafe water and indiscriminate water-contact activities are major factors enhancing continuous spread of schistosomiasis in Nigeria. Many water bodies are prone to contamination with human wastes directly discharged into them or due to surface runoff, and are infested with parasites. Open defecation and discharge of household sewage into water channels is still practiced. Children conduct activities in these water bodies, thereby exposing themselves to infections with schistomes among other pathogens. Urine samples (10 mL each) were collected from 600 consented school adolescents across six Local Government Areas of Kaduna State, Nigeria. Information on their water-contact activities were obtained by means of questionnaires. Urine sediment was examined for Schistosoma haematobium eggs by microscopy. No infection was recorded in adolescents who had awareness about the disease. Those who engaged in swimming (9.2 %, OR=2.2) and fishing (10.3 %, OR=2.1) were significantly more infected than those who did not (P≤0.05). Adolescents who worked on irrigated farms (9.0 %, OR=1.4), washed clothes in rivers (9.0 %, OR=1.6), or fetch water from rivers for domestic purpose (10.0 %) were more infected than others who did not engage in those activities. Therefore, swimming and fishing are important factors enhancing the spread of schistosomiasis among school adolescents in Kaduna State. Irrigation farming, washing of clothes in rivers or fetching water from rivers exposed the adolescents to schistosome infections. Widespread awareness campaigns, provision safe water to communities, and standard water-based recreational centers are paramount

Dengue fever in Nigeria: a mini review

2023-05-15T15:15:17+03:00

Dengue is a disease caused by dengue virus. It is a major mosquito-borne viral disease of humans that is endemic in areas of tropical and subtropical regions, which are environmentally suitable for vector propagation. The disease poses a major threat to the overwhelmed and weak public healthcare delivery system in the developing world, especially in Africa where febrile illnesses are common. The disease undermines the fight against febrile illnesses as infection with dengue often remains undetected or misdiagnosed as malaria or other febrile diseases. This review article highlights dengue epidemiology in Nigeria, dengue transmission dynamics, pathogenesis, diagnosis and current interventions strategies, challenges in addressing dengue infection and future prospects towards dengue elimination. The literature search for publications on dengue virus infection in Nigeria was performed using Google Scholar, PubMed, Web of Science, African Journals Online and other scholarly online databases. Dengue remains a threat to Nigeria and other African countries. In Nigeria, the occurrence of this infection remains a low priority in the public health sector even though it has been reported in about 17 states across the country. The reports of dengue infection in all the geo-political zones suggests active transmission of dengue, hence the need to consider other etiologies of febrile illnesses and engage the public to sustain local involvement as local risk to dengue outbreaks is linked to the population’s knowledge, attitude and behavioral practices that encourage vector breeding