Food Biotechnology
Soheyl Reyhani Poul; sakineh Yeganeh; Reza Safari
Abstract
Introduction: One of the synthetic and harmful preservatives used in sausage is sodium nitrite. Sodium nitrite in meat products helps to increase the storage period and marketability of the product by preventing the growth of anaerobic bacteria, especially clostridiums, exerting an antioxidant effect, ...
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Introduction: One of the synthetic and harmful preservatives used in sausage is sodium nitrite. Sodium nitrite in meat products helps to increase the storage period and marketability of the product by preventing the growth of anaerobic bacteria, especially clostridiums, exerting an antioxidant effect, stabilizing the red color of the meat and improving the taste. Besides these benefits, sodium nitrite is very dangerous for health and it can cause malignant diseases. For this reason, it is necessary to replace this substance with a natural preservative. Pigments extracted from aquatics such as astaxanthin with antioxidant activity, antimicrobial properties and pink color may be a good substitute for sodium nitrite. But these pigments must be nanoencapsulated first due to their sensitivity to food production conditions, including high temperature. The aim of the current research at the first is to extract astaxanthin from Haematococcus microalgae by acid-acetone method and pigment nanoencapsulation with maltodextrin-caseinate combination coating. Then, the nanocapsules produced with different proportions will replace sodium nitrite in the sausage formulation, and oxidative and microbial spoilage tests, color and sensory evaluation will be performed for different treatments.Materials and Methods: First, astaxanthin pigment was extracted from Haematococcus microalgae (Haematococcus pluvialis) using acid-acetone technique. Then, the extracted pigment was nanoencapsulated with maltodextrin-sodium caseinate combined coating and the resulting nanocapsules in the form of treatments A (120 mg/kg sodium nitrite), B (120 mg/kg nanocapsules carrying astaxanthin), C (90 mg/kg sodium nitrite+30 mg/kg nanocapsules carrying astaxanthin), D (60 mg/kg sodium nitrite+60 mg/kg nanocapsules carrying astaxanthin) and E (30 mg/kg sodium nitrite+90 mg/kg nanocapsules carrying astaxanthin) replaced sodium nitrite in the sausage formulation. These treatments were evaluated in terms of oxidative spoilage, microbial spoilage, color indices and sensory properties during 28 days of storage at refrigerator temperature along with the control (without sodium nitrite and nanocapsules). This research was conducted in a completely randomized design. Data were analyzed by one-way analysis of variance and the difference between the means was evaluated by Duncan's test at 95% confidence level. Results and Discussion: According to the results, the lowest levels of thiobarbituric acid and peroxide value during the storage period were related to B, E and D (p>0.05) treatments (p<0.05). A and C treatments had no significant difference in terms of thiobarbituric acid and peroxide until day 14 (p>0.05), but with the passage of time this difference became significant and treatment A showed higher values (p<0.05). The results of this section showed that the power of astaxanthin in controling with oxidative spoilage is significantly greater than that of sodium nitrite, and if the purpose is only to control this type of spoilage, there is no need to replace or use sodium nitrite. The results showed that in the field of controlling microbial spoilage, sodium nitrite has more power than nanocapsules carrying astaxanthin. So that, the lowest amount of total volatile basic nitrogen (TVB-N) and the most standardized pH were related to treatments A, C and D (p>0.05) during the storage period (p<0.05). B and E Treatments (p>0.05) were ranked next (p<0.05). The results of this section showed that if from 120 mg/kg sodium nitrite to 60 mg/kg is replaced with astaxanthin carrying nanocapsules in the sausage formulation, the resulting product has the same antimicrobial power as product containing 120 mg/kg sodium nitrite. Evaluation of the color and sensory properties of treatments showed that A, C and D treatments are at a higher level than treatments B and E and the control in terms of color indices and general acceptance (p<0.05). Comparison of the color and sensory properties of the treatments on days 0 and 28 of storage at refrigerator temperature showed that the color and sensory indices remained constant in the formulated treatments, unlike the control.Conclusions: Nanocapsules carrying astaxanthin with combined maltodextrin-sodium caseinate coating as a natural product with many properties in health, control and prevention of various diseases, have a high efficiency to replace the harmful sodium nitrite preservative in sausage formulation. So that, if 30 to 60 mg/kg of the permissible limit of 120 mg/kg of sodium nitrite in the sausage formulation is replaced with nanocapsules carrying astaxanthin, the resulting product will be similar to the product containing 120 mg/kg of sodium nitrite in terms of shelf life, resistance to oxidative and microbial spoilage, color indices and sensory evaluation.
