Dr. Sajilata Gopalakrishnan, Chief Scientific Officer, Nature Pure Supercritical Extracts Pvt Ltd.
Frozen foods such as frozen bread, meat, vegetables, fries, paneer, cheese, butter, snacks like samosas, ready-to-cook meals, entrées, and chutneys are an excellent alternative to fresh or cooked foods. The frozen food market in India is anticipated to grow at a CAGR (Compounded Annual Growth Rate) of 16 % over the next six years. Western India has the largest share in frozen foods owing to urbanization and increased income of people. North India is expected to show a steady growth and the South Indian market will grow due to the mounting popularity of frozen idli sambar. Frozen vegetables and frozen snacks are anticipated to account for 70% of the total frozen food market by the year 2021. The factors driving the frozen food market are increasing disposable income and a growing number of working women opting for convenience foods.
Frozen foods offer replenishment opportunities in case the consumer runs short of food. Freezing inhibits the growth of harmful microorganisms and pathogens, which cause food spoilage and poisoning. Sous-vide style entrées help easy preparation of dishes such as lamb shanks or beef in a fraction of time compared to the time that would otherwise be taken to cook it. Sous-vide (French for “under vacuum”) is a cooking method that uses food sealed in airtight plastic bags in a temperature-controlled steam environment. Lamb shanks usually take 6 h to cook from fresh raw materials, but using frozen readily-prepared lamb shanks, it takes only half an hour for the dish to be served. Frozen multi-portion ready meals are a convenient option to cater to a large group of people as they can be prepared quickly in a short time period. Also, the growing awareness and concerns amongst consumers over the use of synthetic ingredients have augmented the demand for organic foods and natural food ingredients.
Of late, commercial frozen tomato chutneys on the market have been found to contain paprika oleoresin instead of synthetic colors for the desired red appearance of the product. The oleoresin is extracted from the sweet red peppers (Capsicum annum) and is characterized by minimum pungency and a deep red color owing to the ketocarotenoids. The carotenoids of paprika oleoresin, in addition to contributing a red or orange color to the product also exhibit antioxidative activity. The carotenoids include β-carotene, lutein, zeaxanthin, capsanthin, capsorubin, antheroxanthin, violaxanthin, kryptocapsin, kryptoxanthin, and capsolutein. Encapsulated water-soluble forms with high light and heat stability are also available. The seasoning for French fries, chicken tikka masala, and frozen beef grilling franks usually incorporate paprika oleoresin as a colorant. The other products containing paprika oleoresin include frozen pizza, frozen sausages, and frozen chicken tandoori nuggets.Frozen chicken nuggets consist of natural ingredients in the breader portion, usually made from wheat flour, oil, dextrose, yeast, and paprika extract. Frozen bread stuffing chicken breast meat uses a mixture of paprika oleoresin, annatto extract, and turmeric oleoresin as a coloring agent. Frozen deep paneer makhani, which is paneer prepared in the tandoori style and simmered in a spicy sauce, contains paprika oleoresin as colorant.
Frozen ice cream bars, fudge pops, and popsicles could gain popularity by incorporating curcumin as a yellow colorant in lieu of the synthetic color, tartrazine. In frozen dessert, yogurt bars, and frozen dairy dessert, turmeric oleoresin is used for coloring purpose. Turmeric oleoresin, obtained by organic solvent or CO2 extraction of turmeric (Curcuma longa), is a brownish-orange viscous oily product, widely used as a flavoring and coloring agent. Encapsulation of turmeric oleoresin enhances its stability and facilitates its application in a number of food products.Frozen lemonade usually contains sugar, lemon juice, high fructose corn syrup, citric acid, natural flavor, sodium benzoate, modified food starch, xanthan gum, citrus oils, ester gum, artificial yellow color, and citric acid. Artificial colors may be replaced with natural colors such as curcumin in the water-soluble forms, keeping in mind the adverse effects of synthetic colors.
Essential oils and oleoresin are good alternatives to spices for the flavoring of a wide range of frozen foods. Oregano essential oil finds application in long-term frozen stored turkey meat and sausages. Pimento berry essential oil is also widely used to flavor frozen foods. In an investigation, frozen rainbow trout fillet coated with chitosan enriched with cinnamon oil was found to offer better protection than chitosan coating with regard to oxidative deterioration. Frozen pumpkin cheesecake and pancakes usually contain cardamom, clove, ginger, and nutmeg flavors. These flavors may be produced from spice essential oils with the addition of food-grade emulsifiers or may be spray-dried to a powder form for enhanced shelf life and ease of storage and handling purposes. Frozen chocolate or clove mousse with marshmallow could be incorporated with flavors designed from spice essential oils.
The use of a supercritical fluid (SF) such as CO2 for the extraction of essential oils and oleoresin has received much importance, recently, as it is an effective alternative to conventional processes such as organic solvent extraction and steam distillation and produces an extract with no solvent residues. Under the SF conditions, CO2 has the density of a liquid and solubilizes components like a liquid solvent. Moreover, CO2 has diffusivity similar to gases that enables easy permeation through solid matrices. The solubilization efficiency increases with the density of CO2, allowing dissolution of large amounts of organic compounds, which are recovered from the fluid by reduction of its density at low pressures. The supercritical extraction rate and the extract composition depend on several parameters such as the mechanical or chemical pre-treatment of the material, extractor geometry, operating pressure, temperature, flow rate, and the conditions in the separator where the extracted substances are precipitated from the solutions. CO2, due to its low critical temperature of 31°C, is currently one of the most tapped extraction fluid in the food, aroma, essential oil, and nutraceutical industries.
