by Walid A. S. Gafour
Original Research
The main objective of the current research aimed at evaluating the impact of the manufacturing processes of cow milk such as pasteurization, boiling, ultra-heat treatment, yoghurt fermentation, milk skimming, cream, butter, and ghee production on the degradation of an organophosphate pesticide, Malathion. For that purpose, samples of raw cow milk spiked with Malathion at level 0.5 mg/kg were used. QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was used to extract the malathion-spiked milk samples and HPLC-Photo Diode Array (HPLC-PDA) was used as an analytical tool. The precision of the analytical method was ranged between 90.5-97.8 %. The obtained findings demonstrated that sterilization, and boiling were more effective than pasteurization in Malathion degradation (the degradation efficiency were 91.2, 82.2 and 45.2 %, respectively). Regarding the impact of fermentation, it was found that Malathion degradation increased with the progress of cold storage. It was 56, 80, and 97 % at 1, 7, and 14 days of yoghurt storage. Moreover, a cheese manufacturing also had a positive effect on Malathion degradation where it was 53 and 60.8 % in cheese after 1 and 7 days. The data also displayed that Malathion retained in fatty milk products such as cream (91 %), butter (88 %), and ghee (12.3 %). In view of this, it could be concluded that manufacturing processes such as sterilization, boiling, fermentation and curd coagulation processes had positive impact on Malathion degradation in spiked samples of cow milk.
American Journal of Food Science and Technology. 2018, 6(6), 290-294. DOI: 10.12691/ajfst-6-6-9
Pub. Date: December 22, 2018
3705 Views674 Downloads1 Likes
by Wilbert Long III, Majher I. Sarker and Cheng-Kung Liu
Original Research
This study evaluated the effectiveness of spray washing with aqueous based solution of cinnamaldehyde (CA) and CA plus lactic acid (LA) in reducing aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella from the grain surface of bovine hide so that the developed solutions can potentially be used to decontaminate the cattle carcasses to ensure meat safety. This study also examined the application impacts of the developed formulations on leather produced from the treated hides recognizing the value of cattle byproducts. Two concentrations (0.5% and 0.75%) of CA and LA were used to develop the formulations for 2 to 5 minutes treatment. Research data revealed the fresh cattle hides washed with water alone (control) resulted in recovery of aerobic bacteria of 7.39 and 9.30; Enterobacteriaceae of 5.43 and 5.42; E.coli of 4.88 and 5.50 and Salmonella of 3.81 and 4.65 log CFU per leather panel at 2 and 5 minutes of treatment respectively. Comparing to control, hides treated with CA solution alone resulted in the highest reduction of aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella up to 2.22, 0.42, 0.72 and 1.61 Log CFU respectively for 2 to 5 minutes treatment. The treatment with the formulations of CA plus LA resulted in the highest reduction of aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella up to 2.12, 3.12, 2.33 and 2.28 log CFU respectively for 2-5 minutes of treatments. From microscopic analysis, mechanical and subjective examinations, it was revealed that the leather produced from the formulation treated hides were comparable to the control in terms of structural integrity.
American Journal of Food Science and Technology. 2018, 6(6), 280-289. DOI: 10.12691/ajfst-6-6-8
Pub. Date: December 07, 2018
15691 Views2570 Downloads
by M.W. Ahmed and M.N. Islam
Original Research
Moisture sorption isotherms of commercial wheat flour, rice flour and corn flour were determined within the water activity range of 0.11-0.93 at different temperatures (5°C, 30°C and 55°C) using the static gravimetric method. The moisture sorption isotherm of all flours exhibited type II characteristics according to BET classification. It was found that corn flour had a higher sorption capacity than wheat and rice flour. Temperature influence on sorption behavior was found that, for wheat and corn flour, the sorption capacity decreased with the increase of temperature, while for the rice flour an opposite behavior was observed at water activity value higher than 0.75. The Clausius–Clapeyron equation was used to calculate the net isosteric heat of sorptions. For all flours, the heat of sorption decreased with the increase of EMC.
American Journal of Food Science and Technology. 2018, 6(6), 274-279. DOI: 10.12691/ajfst-6-6-7
Pub. Date: December 04, 2018
12463 Views2514 Downloads
by Booker Osodo, Daudi Nyaanga, Jeremiah Kiplagat and Joseph Muguthu
Original Research
The performance of a forced convection grain dryer may be evaluated based on different criteria, such as drying rate, moisture removal rate and efficiency. This performance is dependent upon various drying parameters, such drying air velocity and temperature as well as grain layer thickness. It is necessary to apply an optimal combination of levels of the various parameters in order to achieve improved performance of such a dryer. This study developed an experimental grain dryer and investigated its performance under different drying conditions. The Taguchi approach was used to determine the optimal combination of drying air velocity, temperature and grain layer thickness that could be used to ensure greatest drying efficiency and moisture removal rate (MRR). ANOVA and LSD tests were used to determine whether change of air velocity and grain layer thicknesses significantly affected drying efficiency as well as MRR.The experimental grain dryer developed was of dimensions 0.5 m x 0.5 m x 1.0 m and was equipped with a 0.7 kW centrifugal fan. It was found that the optimal combination of grain layer thickness and air velocity were 0.04 m and 0.34 m/s respectively for solar drying, if drying efficiency was the determining criterion. When drying was done under laboratory conditions, a combination of 0.41 m/s air velocity, 45°C air temperature and 0.02m layer thickness resulted in greatest MRR and drying efficiency. These findings are useful because use of combination enable the design and use of such a dryer in a manner that ensures minimal energy wastage. Appropriate time management is also facilitated as drying can be undertaken at the shortest possible time.
American Journal of Food Science and Technology. 2018, 6(6), 263-273. DOI: 10.12691/ajfst-6-6-6
Pub. Date: November 23, 2018
7876 Views1408 Downloads
by Zhaohong Ci, Kazuto Kikuchi, Aoi Hatsuzawa, Arisa Nakai, Chengyu Jiang, Atsushi Itadani and Michiyuki Kojima
Original Research
Dietary inhibitors of fats and carbohydrates degrading digestive enzymes can reduce obesity and type 2 diabetes. In this study, we investigated and compared polyphenol content, DPPH radical scavenging activity, and inhibitory activity on digestive enzymes, including α-glucosidase, α-amylase and lipase in flesh, peel, core and seed from mini apple (Malu domestica cv. ‘Alps Otome’). Polyphenol content was significantly higher in peel and seed extracts than in flesh and core extracts. As comparing with flesh, peel polyphenols exhibited stronger DPPH radical scavenging activity, and α-amylase and lipase inhibitory activity. Oligomeric polyphenols (Fra.II) were the main polyphenols in seed extracts, which exhibited significantly strong DPPH radical scavenging activity and inhibitory activity on digestive enzymes. However, monomeric polyphenols (Fra.I) were the main polyphenols in core extracts, which exhibited weak inhibitory activity on digestive enzymes than the other parts. Moreover, Fra.III of seed and peel extracts had the highest inhibitory activity on α-glucosidase, followed by Fra.II and Fra.I, respectively. It indicated that more highly polymerized polyphenols from peel and seed of mini apple showed more potent inhibitory activities on α-glucosidase. All of the observations suggested that mini apples possess useful properties. Particularly, it has potential applications for the treatment of diabetes and obesity.
American Journal of Food Science and Technology. 2018, 6(6), 258-262. DOI: 10.12691/ajfst-6-6-5
Pub. Date: November 15, 2018
10330 Views2569 Downloads
by Fidèle Paul Tchobo, Ali Mahamat Seid, Guevara Nonviho, Reine Zinsou, Mouaimine Mazou and Andriano Jospin Djossou
Original Research
Shea seeds were collected in 8 regions of Chad and the butters of their almonds were extracted by refluxing with hexane. The quality index (acid, peroxide, iodine and saponification index), the acylglycerol and fatty acid compositions and the proportions of phenolic compounds and chlorophylls of these various butters were evaluated by standardized conventional methods. Chad Shea almonds are very rich in butters (average of 54.24 ± 4.89%), especially that of Mandoul (61.18%). These Shea butters have excellent quality index and contain high proportions of triacylglycerols (TAG: 76.15 ± 7.33%). The major TAGs are distearylolylglycerol (SOS: 49.17-54.43%), dioleylstearylglycerol (SOO: 32.29-35.70%), and dioleylpalmitylglycerol (POO: 3.57-4.66%). This profile revealed a minor content of Chad Shea butter in arachidic, gadoleic, and linolenic acid. However, Mandoul Region Shea butter has the highest proportion of phenolic compounds (7.24 mg GAE/100 g), relatively no chlorophyll was found.
American Journal of Food Science and Technology. 2018, 6(6), 253-257. DOI: 10.12691/ajfst-6-6-4
Pub. Date: November 12, 2018
10215 Views2159 Downloads
by Bibiana Igbabul, Ruth Ogunleye and Julius Amove
Original Research
This study was carried out to evaluate the quality characteristics and acceptability of cookies produced from wheat flour and fermented Afzelia africana flour blends in various proportions (100:0 (sample A and control), 90:10 (sample B), 80:20 (sample C), 70:30 (sample D) and 60:40 (sample E). The proximate, physical, mineral, vitamin and sensory properties were determined. The result of the proximate composition showed that there was significant increase (P<0.05) in the protein (6.08 to 12.33%), fibre (1.88 to 5.89%), ash (1.35 to 3.02%), fat (19.29 to 27.06%) and energy (431.29 to 458.78kcal). The carbohydrate content decreased with the addition of fermented Afzelia africana flour and ranged from 41.48-58.34% while the value for the moisture content varies from 9.39 to 13.06% which decreased significantly (P<0.05) with increase in fermented africana flour. The physical properties were ; the diameter (12.25 to 13.50mm), thickness (12.25 to 13.50mm), Weight (19.75 to 18.20g) and spread ratio (3.30 to 3.83) of the cookies. The minerals and vitamins increased significantly at (P<0.05) with the addition of Afzelia africana flour. The result ranged as follows; iron (1.67 to 3.00mg/100g), calcium (15.21 to 116.03mg/100g), zinc (0.55 to 2.98mg/100g), potassium (55.86 to 388.68mg/100g), beta-carotene (1.54 to 2.08mg/100g), vitamin C (0.01 to 0.92mg/100g). The sensory scores showed that cookies produced from 100% wheat flour (sample A and control) compared favourably with the cookies from 90% wheat flour and 10% fermented Afzelia africana flour (sample B), 80% wheat flour and 20% fermented Afzelia africana(sample C), 70% wheat flour and 30% fermented Afzelia africana(sample D), 60% wheat flour and 40% fermented Afzelia africana(sample E) . All the cookies were generally acceptable and scored above 5 on the 9-point Hedonic scale. Therefore wheat flour can be substituted up to 40% fermented Afzelia Africana flour in baking depending on the nutritional needs. This would enhance the utilization of this underutilized crop and help to increase protein, energy and decrease malnutrition problem in developing countries.
American Journal of Food Science and Technology. 2018, 6(6), 247-252. DOI: 10.12691/ajfst-6-6-3
Pub. Date: October 26, 2018
10327 Views2729 Downloads1 Likes
by I.H.W. Surendra, E.M.R.K.B. Edirisinghe and R.M.N.P. Rathnayake
Original Research
The effect of gamma irradiation, followed by storage in ice, on Tilapia (Oreochromis sp.) fillets was investigated by monitoring microbiological and chemical changes after low-dose irradiation (1 and 3 kGy). Control and irradiated samples were stored in ice, and were analyzed at 7-day intervals. Bacterial counts showed that the shelf-life of 3 kGy irradiated Tilapia was extended to 70 days, and 1 kGy irradiated Tilapia had a shelf-life of 56 days. By comparison, control samples had a shelf-life of 7 days. Coliform bacteria was eliminated by 1 kGy irradiation, and was not detected again during the study. Peroxide and thiobarbituric acid levels increased up to the 28th day of storage, and then underwent reductions. The percentage of free fatty acid increased with the duration of storage in each treatment. Saturated fatty acids were significantly reduced with 1 kGy irradiation, whereas 3 kGy and control samples didn’t fluctuate. Levels of monounsaturated fatty acids were significantly increased in irradiated Tilapia, whereas control samples showed reductions with storage. Polyunsaturated fatty acids in Tilapia muscle treated with 1 kGy irradiation showed significant increases over time; however, with a 3 kGy irradiation dose, significant reductions were observed with storage. Palmitic acid (C 16:0), linoleic acid (C 18:2), and docosahexaenoic acid (C 22:6) showed significant reductions with storage. The present study indicates that 1 kGy is the safest irradiation dose for the preservation of Tilapia muscle stored in ice.
American Journal of Food Science and Technology. 2018, 6(6), 237-246. DOI: 10.12691/ajfst-6-6-2
Pub. Date: September 28, 2018
11563 Views2078 Downloads
by Sinda El-Gharbi, Meriem Tekaya, Alessandra Bendini, Enrico Valli, Rosa Palagano, Mohamed Hammami, Tullia Gallina Toschi and Beligh Mechri
Original Research
The effects of geographical location on the chemical composition of olive oil of Zarazi cultivar growing in four different regions in the south of Tunisia (Sfax, Tataouin, Matmata and Medenin) were evaluated. Quality indices, oxidative stability, tocopherol content, fatty acid, sterol and phenolic compositions, were analyzed for each oil sample. Significant differences were detected depending on the growing area (p< 0.05). In general, the main secoridoids, were present in higher levels in the oil obtained from olives of Sfax region. Statistical analyses showed that acidic and sterolic compositions of olive oil were significantly modified according to the growing regions. The Principal Component Analysis of the different analyzed compounds indicated that the factor “geographical location” significantly affected olive oil quality, and highlighted the high quality of oil samples of Sfax, in terms of their high oxidative stability and their richness in bioactive compounds.
American Journal of Food Science and Technology. 2018, 6(6), 228-236. DOI: 10.12691/ajfst-6-6-1
Pub. Date: September 26, 2018
8643 Views1291 Downloads