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  • Five main mechanisms for furan

    2018-11-02

    Five main mechanisms for furan formation have been proposed (Fig. 1), including: (1) the thermal degradation of carbohydrates such as glucose, lactose, and fructose [7]; (2) the Maillard reaction involving the reaction of a specific amino MLN 9708 with a reducing sugar in the presence of heat; (3) the oxidation of polyunsaturated fatty acids; (4) the decomposition of ascorbic acid or its derivatives; and (5) the thermal oxidation of carotenoids [8–11]. Typically, the Maillard reaction involved three stages [12], i.e.: the initial, the intermediate, and the final. The first stage involves the sugar–amine condensation MLN 9708 and the Amadori rearrangement to the so-called Amadori product. The second stage involves sugar dehydration and fragmentation and amino acid degradation especially at high temperatures. In the final browning stage, the intermediates polymerize and unsaturated to form, fluorescent and colored polymers, known as melanoidins are formed. The chief reactions involved in the final stage are thought to be aldol condensation, aldehyde–amine polymerization with the formation of heterocyclic nitrogen compounds. Previous studies have suggested that furan is produced or synthesized or made another work [8,13]. Since Maillard reactions are one potential route of the formation of furan [9–11], factors affecting the Maillard reactions have been thought possibly influence the furan formation [13]. These factors include temperature, duration of heating, pH, water content, type of reactant, the amino acid to sugar ratio, oxygen, and presence of metals, the type of buffer, and the presence of any reaction inhibitors such as sulfur dioxide. Among these, temperature, duration of heating and pH are believed to play crucial roles [14].
    Materials and methods
    Results and discussion
    Conclusion Taken together, the findings suggest that the amount of furan from sugar–glycine model systems during the thermal processing can be attributed to selective sugar types, pH, temperature, and heating time. For glucose–glycine system, furan formed significantly lower (P<0.05) in acidic conditions in comparison with neutral and alkaline conditions when temperatures were greater than 140°C. In the fructose–glycine system, the lowest level of furan was detected in acid condition whereas the sucrose–glycine system had the lowest furan formation in alkaline conditions. In addition, the furan levels were observed to increase with heating time in all three model systems. Furthermore, less furan was generated in non-reducing sugar system (sucrose) than in reducing sugar system (glucose and fructose). These results demonstrate the possibility of limiting the formation of furan in heat processed foods by both the careful selection of carbohydrates (i.e. non-reducing sugars and reducing sugars) ingredients and appropriate processing conditions.
    Acknowledgements The financial support for this study by National Natural Science Foundation of China (No. 30960242), National Basic Research Program of China (973 program) (No. 2012CB720805) and Training Project of Young Scientists of Jiangxi Province (Stars of Jing gang) is gratefully acknowledged.
    Introduction The quality of food products can be affected by lipid peroxidation, which can result in alterations in flavor, texture, color, or nutritive value, or cause potentially toxic reactions in the food during processing and storage. Antioxidant peptides, a class of safe and widely distributed natural antioxidants, have been derived from different protein resources such as porcine plasma [1], jellyfish [2], rice endosperm [3] and algae [4], and can be used to prevent or delay food deterioration and extend the half-life time of foods. In addition to inhibiting lipid peroxidation and the formation of free radicals, antioxidant peptides also exhibit typical characteristics of natural antioxidants compared with synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which have potential side effects. The antioxidant properties of these hydrolysates, such as free radical-scavenging activity and metal ion chelation, have been ascribed to the cooperative effects of multiple properties [5].