| Publisher: Sultan Qaboos University, Oman
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Journal of Agricultural and Marine Sciences
Number of Followers: 0  Open Access journalISSN (Print) 2410-1060 - ISSN (Online) 2410-1079 Published by Sultan Qaboos University, Oman  [4 journals]
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- Assessment of aflatoxin B1 content and aflatoxigenic molds in imported
food commodities in Muscat, Oman
Authors: Alaa Khamis Sulaiman Al-Alawi, Ahad Ahmed Said Al-Mandhari, Issa Hashil Al-Mahmooli, Majida Mohammad Ali Al-Harrasi, Ismail Mohamed Al-Bulushi, Abdullah Mohammed Al-Sadi, Rethinasamy Velazhahan
Pages: 1–6 - 1–6
Abstract: Aflatoxins, mainly produced by Aspergillus flavus and A. parasiticus are considered as serious food safety and human health issues due to their hepatotoxic effects. In the present study, the occurrence of aflatoxin B1 (AFB1), the most potent human liver carcinogen, and prevalence of toxigenic isolates of Aspergillus spp. were assessed in 140 food commodities in Muscat markets, Oman, and the 95 quarantined imported food commodities. These samples consisted of rice, corn, peanut, red chilli powder, soybean, dried dates and tree nuts. AFB1 was analyzed using competitive ELISA/LC-MS and the aflatoxigenic fungi were detected using plating technique followed by molecular identification. No AFB1 was detected in 89 (63.6%) samples collected from local markets, while 44 (31.4%) samples contained 1-5 ppb and the remaining 7 (5%) samples (red chili powder) contained 6-10 ppb. None of the samples exceeded the maximum permissible limit of 10 ppb set for foods by Oman legislation. Of the 95 quarantined samples, only 17 (17.9%) samples were positive and contained AFB1 at concentrations ranging from 1-3.4 ppb. Four isolates of Aspergillus pp. were isolated from the collected samples and were identified as Aspergillus flavus (A14, A16 and A23) and A. chevalieri (A46) on the basis of internal transcribed spacer (ITS) sequences of ribosomal DNA. Among them, A. flavus strain A14 alone produced AFB1 (7.6 ppb), while A16, A23, and A46 were non-toxigenic. This is the first detailed report on the occurrence of AFB1 in food commodities imported into Oman.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp1-6
Issue No: Vol. 28, No. 1 (2023)
- Effect of intermittent frying on the stability of vitamins A and D in
commercially fortified oils
Authors: Mohamed Al-Khusaibi, Seham Al-Amri, Nasser Al-Habsi, MD. Shafiur Rahman
Pages: 7 - 15
Abstract: Fat-soluble vitamins and fatty acids are very sensitive to high temperature and oxidation. In this study, stability of vitamins A and D, and physiochemical changes were investigated in two types of oils, palm olein (PO) and a blend of PO and sunflower oil (OB). The intermittent frying was performed at two different temperatures 160 and 190 °C. Batches of French fries (500 g) were fried in a deep-fat fryer for 5 cycles, a cycle per day. In each cycle, food was fried every 15 min with a total frying time of 5 h per day. Oil samples were taken at the end of each heating cycle to measure vitamins A and D concentration, free fatty acid (FFA), peroxide value (PV) and color. In PO, vitamin A was reduced by 96.7% after 25 h of frying at 160 °C and it was completely depleted after 15 h at 190 °C. In OB, the vitamin was reduced by 72.2% after 25 h of frying at 160 °C; and it was completely depleted at 190 °C at the end of frying cycles. Vitamin D was less stable, its content in PO decreased by 67.0% and 80.0% at 160 °C and 190 °C, respectively, after 5 h of frying. In OB, it was reduced by 50.0% and 67.0% at 160 °C and 190 °C, respectively, after 5 h of frying. It was found that both types of oil and frying temperatures showed significant effect on vitamin A concentration, while they did not show any effect on vitamin D. Red color increased linearly with frying time in both oils, while fried at two frying temperatures. The change in color was significantly associated with the vitamin A depletion. A low, but significant, association was found between color changes and depletion of vitamin D. In conclusion, the stability of these vitamins depended on the types of oil and temperature of frying. These were more stable in OB compared to PO, and similar stability was observed in the cases of FFA and PV.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp7-15
Issue No: Vol. 28, No. 1 (2023)
- Evaluation of Several Chromatographic Resins on the Separation of Dates
Sugar and their Impact on other Compounds in Dates
Authors: Ahmed Al-Alawi, Siham Al-Shaibi, Wesonga Ronald
Pages: 16–2 - 16–2
Abstract: Dates are one of the most important food commodities in the Middle East countries, including the Sultanate of Oman. The fruit is regarded as a highly nutritious and healthy food. However, there are two million tons per year of dates that are abandoned waste worldwide. The objective was to establish an optimized method to separate sugars from dates using chromatographic resins and know the effect of those resins on the other ingredients. Fard date and three strong-cation gel-type resins (DOW-Ca, PCR-Ca and PCR-Na) were used in this study. The free-sugar extracts were analyzed by HPLC-MS method to quantify sugars and polyphenols. Most of the sugars were adsorbed by all of the tested resins with a higher selectivity towards fructose compared to glucose and sucrose. DOW-Ca had the lowest sugar adsorption compared to the others. Minerals profile by ICP detected a sharp reduction in potassium content, which was the main mineral found in Fard dates. Polyphenols content showed drastic decrease after treatment. Overall, the project succeeded in defining a method to remove sugar from dates and extend the loss of minerals and polyphenols in the process. For future work, it is recommended to evaluate the efficiency of other chromatographic resins in sugar separation.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp16-29
Issue No: Vol. 28, No. 1 (2023)
- Seasonal variations of surface mesozooplankton community structure in the
Sea of Oman and the Arabian Sea
Authors: Saud Salim Al Busaidi, Michel René Claereboudt
Pages: 30–4 - 30–4
Abstract: The different characteristics and atmospheric forces over the Sea of Oman and the Arabian Sea are assumed to influence zooplankton seasonality and community structure. This work aimed to characterize the abundances and seasonality of coastal and surface mesozooplankton communities in the Sea of Oman (Muscat) and the Arabian Sea (Salalah), and the effects of environmental factors on their distribution. Zooplankton samples two contrasting coastal regions; 22 in the Sea of Oman, and 20 in the Arabian Sea, were collected during 2013-2014 from the surface and analyzed. Total zooplankton abundance was divided by the number of samples to obtain the monthly average abundance per meter cube (ind•m-3) of sea water. A total of 91 species were observed from all 42 samples of which 58 were copepods, among which 47 were calanoid copepods. Species composition varied significantly between the two locations. The similarity between the two communities was highest (samples were closest to each other) during the winter, and showed the largest differences in composition in the summer. The seasonal changes in community structures were most significant for copepods and calanoid copepods (p= 0.0002 and p= 0.0003 respectively) and less significant for non-copepods (p= 0.0057). Only few species (17 in the Sea of Oman and 20 in the Arabian Sea) represented more than 90% of the total zooplankton abundance. There was a distinct pattern of seasonal variation in the abundance of zooplankton in the Arabian Sea, especially copepods and meroplankton, but there was no such pattern in the Sea of Oman. Some successful species such as Temora turbinata and Penilia avirostris in the Sea of Oman, and Oithona spp. in the Arabian Sea seem able to exploit a wide range of prey from phytoplankton to small ciliates and thus feed through the microbial loop.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp30-46
Issue No: Vol. 28, No. 1 (2023)
- Evaluation of the Intestinal Bacterial Community of Local Omani and Cobb
500 Broiler Chickens Raised in an Open-Sided House Using 16S rDNA-Based
Analysis
Authors: Waleed Al-Marzooqi, Mai A S Al-Balushi, Yasmin El Tahir, Muhammad N Asi, Hani M. El-Zaiat, Mohammed A Al-Abri, Kaadhia Al-Kharousi
Pages: 47–6 - 47–6
Abstract: Little is known about how the intestinal bacterial microbiota differs among different strains of chickens raised in an open sided house, predominantly those with lower growth rates, such as Indigenous chickens. Ninety-one-day-old chicks of each strain of chickens were raised in an open-sided house system and fed a conventional corn-soybean meal diet from Day 0–35 days of age. The objective of this study was to assess the relative abundance of bacteria microbiota identified in the intestinal tract of local Omani and Cobb 500 broiler chickens raised in an open-sided house system using 16S rDNA-based analysis. The results obtained showed the diversity of bacterial populations in different intestinal regions of two chicken strains. Bacilli were found in higher numbers and reached 98.8% of the bacteria in the duodenum on Day 5 in Cobb 500 versus 72.5% in the Omani chickens. Local Omani chickens had significantly higher numbers of Clostridia at an early age period. On Day 5 Clostridia comprised 13.1% of the bacteria in the duodenum of local Omani chickens, versus only 0.062% in the Cobb 500. The relative abundance of the bacterial microbiota differed significantly (p <0.05) across different intestinal segments of the two strains of chickens, suggesting that each region generated its bacterial community with different relative abundances.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp47-61
Issue No: Vol. 28, No. 1 (2023)
- Comparative Study of Ultrastructural Observations on Blood Cells of Local
Omani and Cobb 500 Broiler Chickens
Authors: Waleed Al-Marzooqi, Shadha K. Al-Aufi, Haytham Ali, Hani M. El-Zaiat, Kaadhia Al-Kharousi, Salma R. Al-Adwani, Yasmin El Tahir, Abdulrahman Al Nabhani, Mohamed A. Al Kindi
Pages: 62–6 - 62–6
Abstract: The local Omani chicken represents a long-established indigenous chicken breed in the Sultanate of Oman. Many farmers in Oman raise local chickens for meat and egg production. Therefore, to ensure an enhanced production of local breed chickens, it is important to assess their health performance. The present study was conducted to describe the comparative ultrastructural details of the blood cells of Omani and Cobb 500 chickens. Twenty apparently healthy 35-old birds (10 per strain) of either sex reared at the Poultry Research Unit at the Agricultural Experiment Station, Sultan Qaboos University. The blood was collected from wing vein into tubes containing EDTA as anticoagulant. The blood was further processed for transmission electron microscopic study. The results obtained showed that all blood cells of both Cobb 500 and Omani chicken were similar. The heterophil nucleus had a multi-lobed nucleus. The number of nuclei lobes ranges from 2 to 3. The Eosinophil had a distinctive appearance and mostly had a lobulated nucleus. Basophil was round in appearance and had four types of granules (dense granules, mottled granules, web or net granules and myelin granules) which can be seen clearly. The lymphocytes were the smallest leukocytes and it was characterized as small round cell with few cytoplasmic process. The monocytes were round in shape with kidney-shaped or indented nucleus. The nucleus had more heterochromatin patches compared to euchromatin. The thrombocytes were distinguished from other cells by their dense nucleus and the large vacuoles found in the cytoplasm. In conclusion, this study shows great similarities in the ultrastructure of all blood cells composition between local Omani and Cobb 500 broiler breeds.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp62-69
Issue No: Vol. 28, No. 1 (2023)
- Storage Study on Tomato, Pumpkin, and Ginger Composite Vegetable Squash
Authors: Seyida Afreen Seyid Mohamed Moulana, Premakumar Kanakaraja, Lakmali Ruvini, Lakmali Ruvini, Anoma Senaratna
Pages: 70–7 - 70–7
Abstract: Sri Lanka has a vast variety of vegetables. Although the nutritional and medicinal properties of pumpkin and tomato are acknowledged, their consumption as beverage is limited due to their lack of taste. Blending these vegetables with spice extracts is considered a more nutritious alternative when added to beverages. An effort was completed to determine the storage stability of vegetable squash made using different proportion of tomato, pumpkin and ginger. Considering the findings of several preliminary studies, five formulations in various mixes of tomato and pumpkin, were chosen. The highest scores for all the sensory parameters and chemical characters were obtained by formulation (T1) 50% tomato + 50% pumpkin followed by (T2) 75% tomato +25% pumpkin. The best combination was improved using 1 % ginger to form T3 (50% tomato+ 50% pumpkin+ 1% ginger). The most three promising treatments (T1, T2 and T3) were chosen for a storage experiment at 30°C and 70-75% relative humidity. Compositional analysis and sensory assessments were done. In chemical analysis, it was found that variances in the scores of pH, ascorbic acid, titratable acidity, total sugar and reducing sugar were significant (p< 0.05). Squash formulations showed an increasing trend in titratable acidity (0.43 % -0.64 %), pH (3.37 – 4.08), total sugar (11.78 % - 37.04 %), reducing sugar (4.42 % -31.96 %) and a decreasing trend in ascorbic acid (308.23 mg/100 ml – 79.97 mg/100 ml) and total soluble solids (25.05 -24.3o Brix) as a function of storage time. Sensory analysis revealed significant differences (p<0.05) across formulations for organoleptic characteristics, such as aroma, taste and overall acceptability. The composite vegetable squash T3 was chosen as the best formulation based on the findings of physicochemical and sensory attributes. It could be stored for 12 weeks without any significant variations and prolonged shelf life.
PubDate: 2023-02-11
DOI: 10.53541/jams.vol28iss1pp70-76
Issue No: Vol. 28, No. 1 (2023)
