Open Access Original Research Article

Polycyclic Aromatic Hydrocarbons in Two Commonly Consumed Fresh and Smoked Fishes in Ekiti State and their Effects on Human Health

S. S. Asaolu, A. J. Adesina, A. A. Adebawore, A. A. Araromi

Asian Food Science Journal, Volume 13, Issue 2, Page 1-15
DOI: 10.9734/afsj/2019/v13i230099

Background and Objective: Polycyclic aromatic hydrocarbons have received substantial consideration as an environmental organic pollutant in many continents such as Africa, Europe, and Asia as well as parts of America. Many polycyclic aromatic hydrocarbon compounds have been proven, identified and quantified in nearly all segments of the environment due to their carcinogenicity, mutagenicity, and cytotoxicity even at very low concentrations. The objective of the study was to look at the levels of polycyclic aromatic hydrocarbons in fresh and smoked Scomber scombrus (Atlantic mackerel or Titus) and Trachurus trachurus (horse mackerel or kote in southwestern Nigeria) sold in Ado-Ekiti major markets, Nigeria and also assess the risks involved in their exposure and consumption.

Materials and Methods: Fresh and smoked samples of two selected fishes (Kote and Titus) were taken for this study. They were cleaned and wrapped in aluminium foils, then refrigerated and the homogenized samples were extracted simultaneously by solvent-solid and Soxhlet extraction. The extracts were analyzed for sixteen polycyclic aromatic hydrocarbons using the Agilent 6890N GC-FID/MS. One and 2-way ANOVA and SPSS were employed for the statistical analysis.
Results: The mean total polycyclic aromatic hydrocarbons levels in the fish samples ranged from 0.028 and 0.145 μg/kg. High molecular weight PAHs (HMW-PAHs) were generally predominant compared to low molecular weight PAHs (LMW-PAHs). The LMWPAH/HMW-PAH ratios were < 1 for both samples, indicating anthropogenic, mainly pyrogenic, the origin of PAHs in the sourced environment. Risk assessment conducted using benzo(a)pyrene carcinogenic and mutagenic toxicity equivalency factors (TEF and MEF, respectively) showed low risk (8.69e-08 – 5.93e-07 and 1.02e-07 – 1.83e-07 μg/kg, respectively for carcinogenicity and mutagenicity) associated with consuming both smoked and fresh fish samples were below USEPA guideline (1.0e-05) for potential cancer risk. The mean hazard indexes ranged from 6.77e-08 – 4.61e-07 and were below 1 in line with an acceptable cumulative threshold. Correlation is significant at the 0.01 < P > 0.05 levels (2-tailed). 

Conclusion: This study showed that there are no adverse health effects of PAHs content on consumers of these two fish samples, however, levels of PAHs present in smoked fish may pose elevated cancer risks if consumed at high consumption rates over a long period.

Open Access Original Research Article

Comparison of Vitamin C Content of Commercially Available Fresh Fruits

Aneta Popova

Asian Food Science Journal, Volume 13, Issue 2, Page 1-6
DOI: 10.9734/afsj/2019/v13i230100

Aims: The aim of the current paper is to identify the ascorbic acid level in ten commercially available fruits in order to expand the existing database about fruits rich in Vitamin C and to promote their daily consumption.

Study Design:  Research was conducted experimentally.

Place and Duration of Study: University of food technologies, Plovdiv, Bulgaria, October 2019.

Methodology: Ascorbic acid levels were determined with the use of two oxidation-reduction titration methods – Dichlorophenoliodophenol (DCPIP) and N-Bromosuccinimide (NBS).

Results: All studies samples possessed different amounts of ascorbic acid. Both DCPIP and NBS assay resulted in determining strawberries as the fruit with the highest ascorbic acid levels – 55.1 ± 1.6 mg/100 g and 59.8 ± 2.2 mg/100 g respectively. Lowest values were obtained for fig. All results are commensurable to those obtained in other studies. Ascorbic acid levels were as follows: strawberries > grapefruit > pear > green apple > blueberries > quince > banana > plum > white grapes > fig.

Conclusion: In this study, ten commercially available fruits were studied for their ascorbic acid levels. Comparison between two titration methods showed moderate differences in the results confirming that the NBS method is more sensitive. All reported data confirms that differences occur, but fruits can be considered sources of vitamin C.

Open Access Original Research Article

Effect of Storage Temperature on the Microbial Quality of Fura

Jerry Ampofo-Asiama, Ernest S. Atsrim, Patrick Asiamah

Asian Food Science Journal, Volume 13, Issue 2, Page 1-6
DOI: 10.9734/afsj/2019/v13i230101

Fura, a semi-solid millet-based dumpling, is popularly consumed throughout West Africa. This work was aimed at evaluating the effect of storage temperature on the microbial and physicochemical properties of fura. Freshly prepared fura was stored at 30 and 4°C and sampled periodically to determine the changes in pH, titratable acidity, total soluble solids and total phenolic content. Additionally, the effect of storage temperature on the microbial (by enumerating aerobic mesophiles, lactic acid bacteria, Enterobacteriaceae, and yeast and moulds) quality was determined. Storage affected the acidity of fura with a decrease in pH and an increase in titratable acidity. The total soluble solids and total phenolic content were, however, not affected by storage temperature. Lactic acid bacteria were the predominant microbe present in fura. During storage at 30°C, faster growth of lactic acid bacteria and the other microbes was observed compared to storage at the lower temperature.

Open Access Original Research Article

Antioxidant Content in Solanum Anguivi Lam Berries as Affected by Cooking at Different Stages of Ripening

Caroline Yaya Abbe, Nestor Aboa, Pascal Amédée Ahi, Ghislaine Chépo DAN

Asian Food Science Journal, Volume 13, Issue 2, Page 1-10
DOI: 10.9734/afsj/2019/v13i230102

Aims: In this research changes in vitamin C, flavonoids, polyphenols, tannins contents and antioxidant activity in Solanum anguivi Lam berries during ripening and heat treatment have been studied.

Place and Duration of Study: Department of Food Science and Technology (UFR-STA), University Nangui Abrogoua, between May 2017 and August 2018.

Methodology: The fresh and boiled berries (at 10 and 15 min) were dried and ground to obtain powders. Then, phenolic compounds (tannins, flavonoids and polyphenols), vitamin C were investigated using standard methods. Antioxidant properties were determinated by reducing power (RP), 2,2-diphenyl-1-picrylhydrazyl (DPPH).

Results: Green berries had the highest content in vitamin C (32.23 ± 0.03 mg / 100 g FW), tannins (0.19 ± 0.02 mg tannic acid / 100 g DW), polyphenols (1162.33 ± 0.02 mg GAE / 100 g DW) and antioxidant activity (86.96 ± 0.49%). As far as the berries were ripened, its contents of tannins, vitamin C and polyphenols decreased, like it antioxidant activity. Registered losses were polyphenols (61.2%) > vitamin C (59.8%) > tannins (52.6%) > antioxidant activity (17.88%). While, total flavonoids content increased in red berries. Under boiling times, phenolic compounds, vitamin C and antioxidant activity decreased gradually in the berries. Registered losses in green berries were antioxidant activity (97.86%) > vitamin C (59.78%) > polyphenols (52.39%) > tannins (31.57%). 

Conclusion: Solanum anguivi Lam berries consumed in Côte d’Ivoire contain significant levels of

phenolic compounds, vitamin C and antioxidant activity that are essential for human health but no more 10 min of boiling, this nutritive value were well-preserved.

Open Access Original Research Article

Isolation and Characterization of Pectin from Pumpkin (Cucurbita maxima) Waste and Its Food Application

Jayani Sandarani Maddakandage Dona

Asian Food Science Journal, Volume 13, Issue 2, Page 1-9
DOI: 10.9734/afsj/2019/v13i230104

Pectin was extracted using the method of acid hydrolysis followed by ethanol precipitation at various reaction conditions. Effect of blanching prior to acid hydrolysis, acid types (hydrochloric and citric) and extraction time and temperature combinations were tested to maximize the yield of pectin and they were characterized by assessing physiochemical and functional properties. The feasibility of utilizing extracted pectin in food applications was evaluated. The yield of pectin ranged from 7.30 ± 0.07- 11.04 ±0.01% on a dry weight basis. The results suggested that the highest pectin content is in the fresh pumpkin peel extracted using 0.1 N hydrochloric acid at 80±5℃, 1.25 pH for 1 hour. Water holding capacity, oil holding capacity and emulsifying activity index of pumpkin pectin were 2.5 g/g of pectin (SD 0.46), 1.76 g/g of pectin (SD 0.10) and 0.29 (SD 0.01) respectively. In addition, the degree of esterification, equivalent weight, methoxy content and galacturonic acid content of extracted pectin were 67.64% (SD 0.89%), 978.35 (SD 69.88), 6.55% (SD 0.37%) and 66.46% (SD 1.19%) respectively. Sensory analysis revealed that there is no significant difference in spreadability, surface texture and chewiness of two types of jam prepared using pumpkin and commercial pectin. In conclusion, pumpkin pectin can be categorized as high methoxy pectin.