Food Colorants: Natural vs. Synthetic

Food additives and specifically food colorants have a long historical background in human lives. According to United States Food and Drug Administration (FDA), each dye, pigment or substance capable of imparting color (alone or through reactions with other substances) in food, drug, cosmetics, or to the human body is considered a food colorant. Except for their coloring ability, they are applicable as assurance for food and pharmaceuticals’ safety and quality [1]. Increasing desires of consumers to use natural food provoke a gradual empowerment of the food industry. The industrial goals and consumers’ demands will be obtained as a result of the development and execution of more specific methods in analyzing attractive and sensitive products [2].There are several decisive parameters affecting color loss in foodstuffs such as temperature, light, air, moisture, and storage conditions. Therefore, the critical role of food colorants as an offset for unpleasant color loss or enhancement of the natural color of foodstuffs is undeniable leading to the improvement of foodstuffs’ attractiveness and rising worldwide demands. Nowadays, the market confronts with an increasing need for perfection due to consumers’ preferences. In fact, after doubtless expression of consumers’ interests for natural food additives, the main focus of food industries is to use more natural ingredients and consequently replacement with synthetic ones. Moreover, scientific research works prove the positive relation between natural products consumption and human health improvement while critically adverse effects of synthetic additives banned their usage in some countries [1]. Food colorant is one of the main interesting fields at both industrial and scientific networks led to evident progress. These noticeable advances are typically originated from growing consumers’ demands. Except for the prehistoric use of food additives, they receive significant attention because of their potential to impart color in foodstuffs and also providing health benefits based on scientific observations. Increasing world population and then the need for resources to provide their food had led to the development of numerous synthetic food colorants. However, their short and long-term toxicity and health impairment promotion caused them to be prohibited. As a consequence, consumers ask for the usage of natural food grade pigments instead of synthetic type [3, 4].Synthetic food colorants are chemically synthesized substances used in countless foodstuffs to fascinate consumers. Although their usage is recently prohibited in the food industry, extensive amounts of these colorants are widely consumed and also studied in terms of safety, adverse effects, and toxicity. In terms of safety, their usage must be confirmed by regulator administrations in the food industry. Recently, FDA and EFSA established acceptable daily intake doses and E codes for these currently approved food colorants which are summarized in table 1 [5, 6]. The majority of foodstuffs which contain these colorants such as beverages, candies, and preserved meat and fish products are widely consumed in everyday life. So it must be highlighted that the cumulative effects of their daily intake can be considerable. Thereby, the risk of organic saturation and as a result, side effects and toxicity will be noticeably multiplied [1, 4].Being safer, exerting two or more health benefits (some food additives which are responsible for imparting color in foodstuffs, exert antioxidant activities and act as preservatives), and providing organoleptic features make natural food colorants promising alternatives to chemical dyes. As a matter of fact, legislation and the reassurance of human safety and health level cause proper regulatory guidelines to be developed. Modern consumers are currently more eager to choose natural ingredients containing food for their pleasant properties to prevent diseases than their appealing appearances. In this respect, natural food colorants not only provide organoleptic characteristics but also acts as nutritional and health promoters [1].Based on the literature, natural colorants derive from three main sources: plants, animals, and microorganisms that approved ones are summarized in table 2 [5, 6]. The most common type is plant-derived pigments which can be extracted from different parts of the plants such as roots, stems, leaves, fruits, flowers, stigma, and so on. Anthocyanins are the most widely studied plant-derived colorants, being obtained from flowers, fruits, leaves and even whole plants. It is remarkable to mention that external interferences (pH, temperature, humidity, salinity, stress conditions, and even storage conditions) highly influence the color hue of this pigment. Based on affecting parameters, the anthocyanins color may vary from red to purple and blue. Betalains are the most commonly studied and betanin as a member of this group was already approved to be safely used. They can be widely found in roots of Beta vulgaris L., fruits of Hylocereus polyrhizus (Weber) Britton & Rose, Opuntia ficus-indica [L.] Miller, Opuntia stricta (Haw.) Haw., and Rivina humilis L.Another group of naturally-derived food colorants is carotenoids which are mainly famous for their prominent coloring properties and biological activities. Moreover, their antioxidant activity is widely known and scientifically surveyed, let them consumed as natural preservatives in large scale by the food industry. In the food industry, carotenoids are particularly used in foodstuffs with high fatty acid content in order to prevent the oxidation process. Most carotenoids are from plant origin but there are some investigations that show they can be derived from algae/microalgae, fungus/yeasts, and aquatic animals. Phenolic compounds are another promising class of natural food colorants including Flavanones (naringin), flavones (4,5,7-trihydroxyflavones and apigenin), and flavonols (fisetin, myricetin, myricitin, quercetin, and rutin). Among them, only myricetin and myricitrin are plant-derived compounds isolated from Myrica cerifera L. roots. There are several bacterial/fungal/algal food colorants under investigations. One of these pigments is yeast-derived colorant produced by the genus Monascus. It can produce several azaphilone compounds (monascin, ankaflavin, monascorubrin, monascorubramine, rubropunctatin, and so on) and monacolins (K, L, and M) gave them numerous biological activities but there isn’t any report on safe amount of it in foodstuffs and also no E code has been established yet [1]. Although recent studies are focused on their composition and influencing factors, search for rich plant and microbial sources or increasing the pigment content, assessing and improving stability and bioavailability, processing effects, and health benefits, earlier explorations surveyed the color they impart.

کلیدواژه ها:

FDA ، food colorants ، natural ، synthetic.