Food Technology
Parisa Feizi; Yahya Maghsoudlou; Hoda Shahiri Tabarestani; Seyed Mahdi Jafari; Amir Bahri
Abstract
Introduction
Astaxanthin is a widely used carotenoid pigment in the food industry which is extracted from various natural and synthetic sources. Nowadays, due to the adverse effects of organic solvents green solvents which are non-toxic, non-volatile and environmentally friendly have been proposed. ...
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Introduction
Astaxanthin is a widely used carotenoid pigment in the food industry which is extracted from various natural and synthetic sources. Nowadays, due to the adverse effects of organic solvents green solvents which are non-toxic, non-volatile and environmentally friendly have been proposed. Therefore, this study focuses on comparison of the extraction of astaxanthin from shrimp (Fenneropenaeus merguiensis) and Gammarus (Pontogammarus maeoticus) under soaking conditions for 24 hours with organic solvent (combination of ethanol with ethyl acetate), green solvent (microemulsion of ionic liquid in water) and vegetable oil (sunflower oil). Ionic liquid microemulsion in water is considered a newnovel solvent for astaxanthin extraction. Determination of density, conductivity and diameter were the characteristics of microemulsion test. In extraction,Solvent to sample ratios of 5x, 12.5x and 20x were used for the extraction and compared with the control sample.
Materials and Methods
merguiensis and P. maeoticus With species approval were procured from Persian Gulf Ecology Research Institute (Iran). Commercial astaxanthin (>98 % purity), α-diphenyl-β-picrylhydrazyl (DPPH), and butylated hydroxytoluene (BHT) were procured from Sigma-Aldrich (USA). The HPLC grade ethanol, propanol, ethyl acetate,, tributyl octyl phosphonium bromide, Triton X-100, and n-butanol were obtained from Merck Chemicals Co. (Germany). Refined sunflower oil which was antioxidant-free, was also purchased from Hayat Company (Iran). The shell of F. merguiensis and P. maeoticus were carefully washed with distilled water, then freeze-dried (Christ-Alpha 1–4, LD freeze dryer, Germany) for 48 h at -50 °C. After sieving the powders with a laboratory sieve with a mesh smaller than 15 µm. The obtained powders were kept at Refrigerator. All experiments were done in the Food and Drug Administration Department of Hormozgan University of Medical Sciences.
Results and Discussion
According to the results, the density of the microemulsion was determined in the range of 0.97151 g/cm3, its diameter was 15.8 nanometers and the conductivity was 312 microsiemens at 27.1°C. The results of astaxanthin extraction with different solvents in the comparison with control solvent were statistically significant (p< 0.05). According to the results obtained from the extraction of astaxanthin from two sources of shrimp and gammarus, shrimp was selected as the source with the highest amount of extracted astaxanthin. The use of green solvent (ionic liquid microemulsion in water) in a ratio of 12.5 times solvent to sample was also chosen as the optimal method. The amount of astaxanthin extracted under optimal conditions was 77.44 ± 1.09 mg/ml. The results of DPPH radical inhibition by extracted astaxanthin using ionic, oily and organic solvents compared to synthetic antioxidant BHT showed that the antioxidant activity increased with increasing the concentration of astaxanthin, but this increase was always lower than BHT.
Conclusion
In general, the results of this research show that the use of microemulsion based on ionic liquids is a suitable alternative to conventional methods in extracting and recovering astaxanthin from natural biological sources.
Acknowledgement
We are grateful to the Honorable Vice-Chancellor of Hormozgan Food and Drug Administration for the help in using the Hormozgan Food and Drug Laboratory to conduct the experiments of this doctoral thesis.
Food Biotechnology
Soheyl Reyhani Poul; Sakineh Yeganeh; Zeynab Raftani Amiri
Abstract
Introduction Since heat treatments and special standards are not used in the production of traditional (homemade) tomato paste, fungal and bacterial spoilage in the product occurs extensively during storage in the refrigerator (4°C). Astaxanthin extracted from aquatics has antimicrobial activity ...
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Introduction Since heat treatments and special standards are not used in the production of traditional (homemade) tomato paste, fungal and bacterial spoilage in the product occurs extensively during storage in the refrigerator (4°C). Astaxanthin extracted from aquatics has antimicrobial activity and color similar to tomato and can probably be effective in preventing spoilage of tomato paste. In addition, astaxanthin has other properties in the field of preventing and controlling diseases and maintaining human health, which justifies its use in food formulations as an enrichment. Since heat, enzyme, acid, etc. treatments are practiced during the production of tomato paste, these factors may change the structure and thus the function of astaxanthin. For this reason, astaxanthin nanoencapsulation is necessary for its use in tomato paste formulation. Materials and Methods In this research, first, astaxanthin was extracted from Haematococcus pluvialis microalgae using the acid-acetone combined method. Then, this pigment was nanoencapsulated using maltodextrin-sodium caseinate coating and the resulting nanocapsules were used together with the pure form of astaxanthin in the formulation of tomato paste. The research treatments were control, tomato pastes containing 3 and 6% astaxanthin (A and B, respectively) and also 3, 6 and 9% nanocapsules carrying the pigment (C, D and E, respectively). These treatments were kept at refrigerator for 28 days and were evaluated (on days 0, 7, 14, 21 and 28) in terms of the total number of fungi, Howard's number (HMC), pH, fungal flora, total bacteria count, amount of lactic acid bacteria and sensory properties. This research was conducted in a completely randomized design. Data were analyzed by One-way Anova and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion The results showed that the fungi proliferation, total count and lactic acid bacteria were slower than the control during the storage period in the treatments containing astaxanthin and its carrying nanocapsules, and the minimum number of the mentioned microorganisms and Howard's number were related to treatments D and E (p>0.05). Treatments C, B and A were ranked next in this respect (p<0.05). The number of fungi in two treatments D and E from day 0 to 28 varied from 128 to 332 cfu/gr. Also, the Howard number of these treatments was recorded from 18 to 34% in the mentioned time period. However, these two indices in the control ranged from 121 to 792 cfu/gr and 18 to 91%, respectively, during the storage period. The count of total bacteria and the amount of lactic acid bacteria in the control on day 28 were equal to 8.9 cfu/gr and 311 mg/kg, respectively, but these two values were recorded in the E and D treatments on the same day, about 4.8 cfu/gr and 110 mg/kg, respectively. Counting the total number of fungi, bacterias and also Howard's number in control and other treatments showed that the effect of nanocapsules carrying astaxanthin on microbial growth and proliferation is significantly greater than pure astaxanthin (p<0.05). The pH of the treatments varied from 3.9 to 5.8 during the storage period and the most standardized pH (3.9-4.4) was recorded in C, D and E (p>0.05) treatments (p<0.05). The pH of two treatments A and B (p>0.05) was higher than the three mentioned treatments and lower than the control (p<0.05). This finding showed that nanocapsules carrying astaxanthin have a greater effect on controlling the pH of tomato paste than pure astaxanthin during storage at refrigerator (p<0.05). The identification of the fungal flora of the treatments on the 28th day confirmed that two genus of Penicillium and Aspergillus form the main flora of the product. The results of the sensory evaluation of the treatments on day 0 showed that adding astaxanthin and its carrier nanocapsules does not change the color, aroma, taste and texture indicators (subsequently the general acceptance) of tomato paste (p>0.05). On the 28th day, the mentioned sensory indices only in the two treatments D and E were not significantly different from the 0 day, but they changed negatively in the other treatments (p<0.05). Conclusion According to the findings of the present research, astaxanthin extracted from Haematococcus pluvialis microalgae has the ability to inhibit fungal and bacterial spoilage and stabilize the sensory properties of tomato paste stored at refrigerator. This properties were improved by adding nanoencapsulated pigment using maltodextrin-sodium caseinate combined coating. Since there were no significant differences between the two treatments containing 6% and 9% of nanocapsules carrying astaxanthin (D and E) in terms of quality indices and microbial spoilage, therefore, the treatment containing 6% nanocapsules is introduced as the optimal treatment.
