Effect of different reheating processes and conditions on the nutritional, functional, and microbiological properties of cow meat.

The objective of this study was to evaluate the effect of different reheating methods and conditions on the proximate composition, mineral content, oil quality, and functional and microbiological properties of cow meat. For this, a survey was carried out to identify the reheating methods used in the community. For this study, 8.6 kg of raw beef was used and group 1 (500 g) served as raw control. The remaining 8.1 kg was boiled for 30 min in 5 L of water. Four hundred grams of boiled beef was removed and served as cooked control (group 2). The remaining 3688 g was divided into four groups of 922 g, which were, respectively, divided into subgroups of 307 g. The four sets of subgroups were, respectively, reheated by boiling, frying, microwaving and oven roasting for 3 days. Reheating was done three times a day and samples were collected at the end of each day for further analysis. Changes in proximate composition, mineral content, oil quality, functional properties, and microbiological count were evaluated using standard methods. Results showed that frequent reheating of food was the most used preservation method of cooked food, and boiling and steaming were the most used methods. Reheating time significantly reduces the protein, mineral content, and oil quality of cow meat in general. For the functional properties, reheating methods/conditions generally increased the water-holding capacity, loose and packed bulk densities as well the pH of the meat. Reheating by frying increased the porosity and Hausner ratio of the meat powder while all the reheating treatments reduced the swelling capacity and titratable acidity of cow meat powder. Generally, the reheating methods and duration significantly reduced the bacterial count of cow meat powder. Cow meat should not be reheated for more than 2 days in order to preserve its physiochemical properties.

The effect of soursop-flower-enriched fried palm olein on some biochemical and hematological parameters of rats.

This work set out to, first, assess the role of soursop flower extracts (SFE) in limiting palm olein oxidation during the production of plantain chips, before ascertaining the effect of these soursop-flower-enriched fried palm olein on some biochemical and hematological parameters of rats. The extracts were added to 1.5 kg of oil at 1000, 1400, and 1800 ppm, while BHT at 200 ppm served as a positive control (PO+BHT), and the oil without additives was the negative control (PO). The samples were subjected to 15 frying cycles. Total oxidation values varied between 5.94 ± 0.0 and 31.58 ± 0.37; 8.08 ± 0.25 and 28.24 ± 0.00 and 13.71 ± 0.24 and 42.71 ± 0.40 respectively for palm olein enriched with SFE, for PO+BHT and for PO. Twenty-one groups each comprising five rats received, through dietary supplementation, oils subjected to 0, and 5, 10 and 15 frying cycles for a duration of 30 days. The alanine transaminase and aspartate transaminase of rats fed with oils enriched with SFE at fresh states and at 5 frying cycles was comparable to that of the neutral control group (23.45 ± 2.65 and 93.10 ± 3.53 U/L) and lower than that of the negative control group (52.15 ± 2.01 and 124.07 ± 1.89 U/L). The HDL cholesterol of these animals was also comparable to that of the neutral control group (67.82 ± 4.06 mg/dl) and higher than that of the negative control group (50.25 ± 5.20 mg/dl). White blood cells and mean corpuscular volume of rats fed with fried olein previously enriched with SFE were lower than those fed with fried olein without additives. These extracts are recommended as natural antioxidants for the stabilization of palm olein.

Effect of boiling and oven roasting on some physicochemical properties of sunflower seeds produced in Far North, Cameroon.

The effects of different processing methods on proximate composition, total phenolic content, antioxidant activity, lipid oxidation, and mineral contents of sunflower seeds produced in Far North Region of Cameroon were evaluated. Mean moisture, ash, lipid, protein, fiber, and carbohydrate contents of raw sunflower seeds were 6.60%, 2.55%, 44.65%, 20.17%, 4.08%, and 21.25%, respectively. The changes in moisture, ash (excepted in boiled samples), lipid, protein, fiber, and carbohydrate (excepted in roasted samples) were found to be significant for all cooking methods. Ash and lipid contents of samples roasted at 120°C were found to be significant when compared with other cooking methods. Antioxidant activity increased with treatment. After processing, the acid, peroxide, and thiobarbituric acid values increased significantly, whereas iodine value decreased. The roasting process improved the induction time, and samples roasted at 120°C were found to have the highest induction time (2.29 ± 0.09 hr). Raw sunflower seeds were good sources of potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn), and manganese (Mn). Increase in contents of Ca, Mg, Zn, Cu, and Fe was observed during processing. Roasting compared with boiling appeared to be the best cooking method of sunflower seeds concerning nutrient content, antioxidant stability, and lipid stability.

Effect of oven and sun drying on the chemical properties, lipid profile of soursop (Annona muricata) seed oil, and the functional properties of the defatted flour.

Soursop seeds present a potential source of edible oil production. This work was aimed at determining the effect of oven and sun drying on the chemical properties and lipid profile of soursop seed oil as well as the functional properties of the defatted seed flour. The chemical properties, lipid profiles, and functional properties of soursop seeds dried for 0, 6, 12, 18, 24, and 30 hr, and 0, 1, 3, and 5 days, respectively, in the oven and on the sun using time T0 as the control sample were determined using oil quality indices, gas phase chromatography, and functionality tests for flours, respectively, with a view of highlighting the potentials of the defatted seed. The result of the study revealed that the chemical properties of oils for oven-dried and sun-dried seeds changed with drying technique and time, with iodine value being the more affected parameter, and peroxide value (PV) being the least. The control exhibited the highest free fatty acids (FFAs), peroxide value (PV), thiobarbituric acid (TBA) value, and saponification value compared with dried samples. The fatty acid profiling showed that the predominant fatty acids were C18:1n-9, C18:2n-6, and C16:0 and that unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and omega-fats were not significantly affected by the oven drying time. The mean PUFA content ranged from 31.72% with sundried seeds to 30.92% after 30 hr of oven-drying and was not significantly affected by the drying technique. The oils contained more n-6 (30.60%) fatty acids than n-3 (1.12%). The PUFA/SFA ratios [1.14-1.37] as well as the Atherogenic index (AI) [0.25-0.27] were acceptable because of the recommended range of FAO/WHO. PUFA/SFA, n-6/n-3, and Atherogenic index (AI) did not change much with the sun-drying technique compared with oven-drying. Flours from sun-dried seeds had better functional properties than oven-dried and more than 3 different types of proteins (based on isoelectric points of proteins). It can be concluded that soursop seed contains good quality oil, which can be exploited to improve nutrition. Manufacturers of animal feeds should explore the agro-industrial use of its oil and defatted seed flour.

Effect of boiling and roasting on the physicochemical properties of Djansang seeds (Ricinodendron heudelotii).

This study was aimed at determining the effect of boiling and roasting on physicochemical properties of Djansang seeds. Dried Djansang seeds were divided into three groups: one group was boiled for 5, 10, and 15 min; another group was traditionally roasted for 5, 10, and 15 min, and the last group was left unprocessed and served as the control. Polyphenols were extracted from the processed seeds using the maceration method, and their content and antioxidant activity were evaluated. Oils were extracted from the dried seeds by Maceration method, and the quality was analyzed by determining their peroxide value (PV), thiobarbituric acid value (TBA), iodine value (IV), and acid value (AV). The changes in proximate composition and mineral content of the processed samples were also evaluated using standard methods. Results showed that traditional roasting significantly decreases (p < .05) the polyphenol content and antioxidant activity of Djansang seeds as compared to boiling. The analysis of oil showed that traditional roasting and boiling significantly reduce the quality of Djansang seed oil (PV: 10.85-38.49 meq O2/kg; TBA: 1.80-3.20 ppm; AV: 0.28%-0.82%; and IV: 104.27-98.11 g I2/g for roasted samples, and PV: 10.85-27.52meq O2/kg; TBA: 1.45-2.28 ppm; AV: 0.56%-0.96%; and IV: 105.87-102.96 g I2/g for boiled samples) compared to the control (PV: 9.96 meq O2/kg; TBA: 1.01 ppm; AV: 0.11%; and IV: 104.83 g I2/g) and that traditionally roasted samples were the most affected. The proximate and mineral composition of Djansang was also affected during processing. Boiling for 5 and 10 min (BNS 5 min and 10 min) and traditional roasting for 5 min (TRNS 5 min) appear to be the best processing methods of Djansang for production of Djansang-based foods like Djansang sauce.

Passiflora edulis seed oil from west Cameroon: Chemical characterization and assessment of its hypolipidemic effect in high-fat diet-induced rats.

In this study, the in vivo hypolipidemic effect of west Cameroonian Passiflora edulis variety seed oil (PE) was assessed in female and male Wistar rats. The chemical properties of the oil were evaluated through the determination of the peroxide, iodine, and thiobarbituric acid values, as well as its fatty acid composition using gas chromatography. Results showed that the oil extraction yield was 19.90% and its quality indexes were as follows: peroxide value = 2.10 ± 0.20 meq O2/kg; thiobarbituric acid value = 0.25 ± 0.00 ppm; and iodine value = 97.40 ± 0.45 g I2/100 g. Its fatty acid composition showed that it contains about 84.88% of unsaturated fatty acid, linoleic acid being the most represented (68.39%), followed by oleic acid (14.31%). The administration of this oil resulted in a significant reduction (p < .05) in the level of triglycerides, total cholesterol, and low-density lipoprotein-cholesterol in rats. The PE groups showed a significant increase (p < .05) in high-density lipoprotein-cholesterol compared with untreated male rats. A similar trend was observed with female rats for triglycerides, but lowest values were observed with olive oil at 1 ml. This study suggests that P. edulis seed oil is rich in linoleic acid, which might be responsible for its hypolipidemic effect comparable to that of olive oil.

Alteration of the lipid of red carp (Cyprinus carpio) during frozen storage.

The aim of this study was to determine the oxidative stability of oil extracted from red carp fish frozen up to 9 months at -18°C. To assess oil stability of red carp fish, the analytical indexes and Fourier transform infrared (FTIR) spectroscopy were used. These methodologies used provided similar conclusions. Before frozen storage, the composition of fatty acids showed that red carp oil is a good source of polyunsaturated fatty acids (PUFAs) such as linoleic acid (C18:2ω-6: 5.29% of total fatty acid), linolenic acid (C18:3ω3: 3.53% of total fatty acid), arachidonic acid (C20:4ω6: 3.68% of total fatty acid), eicosapentaenoic acid (C20:5ω-3, EPA: 4,06% of total fatty acid), and docosahexaenoic acid (C22:6ω-3: 3.02% of total fatty acid). During frozen storage, the free fatty acid and peroxide value increased, respectively, from 1.35% to 8.06% in oleic acid and 3.77 to 18.62 meq O2/kg in lipid, while the ratio of PUFA/SFA and polyene index decreased, respectively, from 0.58 to 0.25 and 0.30 to 0.09. The triglycerides also decreased with frozen duration. Therefore, for good fish quality, red carp fish must be stored for <3 months at -18°C.

Effect of Boiling and roasting on lipid quality, proximate composition, and mineral content of walnut seeds (Tetracarpidium conophorum) produced and commercialized in Kumba, South-West Region Cameroon.

The effect of boiling and roasting on the lipid quality, proximate composition, and mineral content of African walnut seeds (Tetracarpidium conophorum) was assessed. Results indicated that the quality of walnut oil significantly (p < .05) reduces with the treatments. Oils extracted from DBWN 60 min (Dried and boiled walnuts 60 min) and FBWN 60 min (Boiled fresh walnuts 60 min) were the most altered. The proximate composition and mineral content of walnut seeds was also significantly affected (p < .05) by the treatments. This study reveals that, thermal processing has significant effects on the nutrients and quality of lipids of walnut oil. DTRWN 60 min (Dried and traditionally roasted walnuts 60 min), DORWN 60 min (Dried and oven roasted walnuts 60 min), and TRFWN 30 min (traditionally roasted fresh nuts 30 min) are the best methods for cooking walnut because they preserve the quality of its lipids and some of the nutrients.

Valorization of soursop flowers (Annona muricata L.) as potent source of natural antioxidants for stabilization of palm olein during accelerated storage.

This study investigates the effect of soursop flowers methanolic extract on the physicochemical characteristics of palm olein during accelerated storage. After analysis of the extract by determining its total phenolic content by colorimetry and identification of some of its phenolic antioxidants by HPLC-DAD(Diode Array Detector), preliminary antioxidants tests have been done. After that, the extract was added in palm olein at concentrations 200-1800 ppm. BHT, at 200 ppm served as standard besides the Control. Induction time, peroxide, p-anisidine, Total oxidation (TOTOX), thiobarbituric acid and iodine values, as well as changes in linoleic acid profile Gas Chromatography/Flamme Ionization Detector (GC/FID) of oil during the storage were evaluated. Results showed soursop flower extract to be rich in phenolic antioxidants and to be efficient, at all concentrations, in delaying palm olein oxidation on Rancimat and accelerated Schaal oven test of 30 days at 70°C. Soursop flowers might be used as potent source of antioxidants for the stabilization of palm olein.