Part of the book: Food Industrial Processes
Part of the book: Food Industry
Carotenoids are the most widespread pigments in nature, extremely important for human health, but are highly unstable molecules especially when exposed to light, oxygen and heat. Many authors report the carotenoid's importance, mainly its pro‐vitamin A (α‐ and β‐carotene) and, additionally, the antioxidant capacity of some of them. Currently, more than 600 carotenoids are known and characterized by their chemical structures. In vegetables, common pro‐vitamin A carotenoids include β‐carotene and its 9, 13 and 15 isomers, α‐carotene and β‐cryptoxanthin. Other common carotenoids such as lycopene, lutein and zeaxanthin do not have pro‐vitamin A activity but serve as natural antioxidants. They are found in many fruits and vegetables such as carrots, yellow sweet potatoes, yellow sweet cassava and pumpkins. Normally, in these plant materials, the β‐carotene is the most abundant. It is still used as natural food coloring, which is not very expensive, since enough 3–5 g of β‐carotene is used to impart a yellow color characteristic of a ton of margarine. There is also a description of its importance in the formation of compounds responsible for flavors that are of interest fragrance and food industries. The purpose of this chapter is to report the presence of pro‐vitamin A carotenoids, mainly the β‐carotene in pumpkins, yellow sweet potato and yellow sweet and bitter cassava.
Part of the book: Carotenoids
Carotenoids are rich sources of pro-vitamin A. These compounds are usually obtained from pumpkins (Cucurbita maxima, C. pepo, and C. moschata), as well as orange and yellow sweet potatoes. Carotenoids are C40 tetraterpenoids, which stand out for their antioxidant activity. Among them are carotenes (very apolar carbon and hydrogen molecules, like lycopene, β-carotene, α-carotene) and oxygenated derivatives and xanthophylls composed of oxygenated functions (less apolar molecules such as lutein, zeaxanthin, cryptoxanthin). β-Carotene is the most commonly found carotenoid, accounting for 25–30% of the total carotenoid content of plants. It is also the most active carotenoid, with the highest bioconversibility in the human body. β-Carotene is a suppressor of tumorigenesis in the skin, lung, liver, and colon, promoting the cessation of the cell multiplication cycle. Thermal processing can affect the sensory characteristics and the antioxidant compounds, altering the antioxidant potential of foods. Time, temperature, and style of cooking are determinant conditions for the increase or decrease of total antioxidant activity. The biological activity of carotenoids depends on their bioaccessibility and solubilization in the gastrointestinal tract. The purpose of this chapter is to offer information about some raw plant materials containing carotenoids.
Part of the book: Progress in Carotenoid Research
Starch applications in food systems are mainly influenced by solubility, gelatinization, paste viscosity, digestibility, and retrogradation. These characteristics result from properties such as the size and shape of granules, amylose and amylopectin contents, distribution of polymer chains, degree of crystallinity, and extraction of waste. In beans, the percentage of starch contents on dry basis is between 45 and 60%, being 24–65% amylose. This chapter evaluated the structure of common beans starch granules (Phaseolus vulgaris) and cowpea (Vigna unguiculata) in raw and cooked forms, by optical microscopy (OM) and scanning electron microscopy (SEM). Thus it was possible to observe the gelatinization of the starch granules especially in cowpea and carioca beans, as well as the “hard-to-cook” phenomenon in the black beans.
Part of the book: Legume Crops