Prospects of Maize (Corn) Wet Milling By-Products as a Source of Functional Food Ingredients and Nutraceuticals

Abstract

Maize (corn) consists of distinct parts, germ, endosperm, and pericarp, with different chemical compositions. During the maize wet milling process, the maize is disintegrated into the main product starch and by-products, including corn germ, corn fiber and corn gluten (the technical term for corn endosperm specific proteins and not the same as wheat gluten). These by-products are used as low-value animal feed products. The corn germ contains high amounts of tocols and phospholipids, while the corn gluten is rich in carotenoids and the corn fiber fraction is rich in phytosterols and complex carbohydrates. Each by-product has the potential to serve as a precursor in the manufacture of functional food ingredients or nutraceuticals that have antioxidant, anti-inflammatory, hypocholesterolemic, hypolipidemic and hypoglycemic properties. These food ingredients/nutraceuticals can be obtained through physical, chemical or enzymatic processes. Some nutraceuticals and food ingredients with market potential include corn fiber gum, oil, arabinoxylans, and xylo-oligosaccharides from corn fiber; corn germ oil and phospholipid ester from corn germ; and carotenoids and oligopeptides from corn gluten. This review focuses on current and prospective research into the use of corn germ, corn fiber and corn gluten in the production of potentially high-quality food ingredients or nutraceuticals.

Genetic Variability of Tocol Content in a Genebank Collection of Temperate Maize Inbred Lines from Southeastern Europe

“…The correlation between the kernel hardness and γ-tocopherol, the total tocopherols and total tocols, was slightly stronger with correlation coefficients of 0.36, 0.37, and 0.38, respectively. In fact, since tocols are predominantly present in the maize germ [45], while kernel hardness in maize reflects the proportion of vitreous hard endosperm in the kernel [47,48], a relatively weak correlation was found in the present study between the kernel hardness and the content of different tocols was expected. Some previous studies in maize have investigated the relationship between the kernel hardness and kernel carotenoid content [20,47,48], but studies reporting the association between the kernel hardness and tocol content are lacking.…”

“…Similarly, in the study by Das et al [29], 44 maize inbreds with yellow/orange-colored endosperm had significantly higher γ-tocopherol and total tocopherol contents than 10 maize inbreds with white endosperm types. The weak correlation found in the present study between the content of tocols and the kernel color is to be expected knowing that tocols are predominantly present in the maize germ [45], while kernel color is related to the carotenoids found in the aleurone, phlobaphenes that accumulate in the pericarp, and anthocyanins found in the pericarp and in small amounts in the aleurone [46].…”

Aflatoxin B1 Degradation by Ery4 Laccase: From In Vitro to Contaminated Corn

“…It may encompass the tempering step, in which water is added to faster separate corn tissues and obtain fractions with low fat content, suitable for the manufacture of extruded products. In wet milling process, the kernels are steeped in SO 2 and lactic acid solution for 24–48 h to facilitate the separation of kernel’s components [ 21 ]. In a complex matrix, such as corn flour, the addition of exogenous antioxidants could be investigated to support mediator reconversion and reduce the oxidative damage induced by the laccase mediator systems (LMS).…”

Multi‐omics‐driven advances in the understanding of triacylglycerol biosynthesis in oil seeds

“…Although the contents of trace elements and active compounds in major oilseeds are very low, their activities confer some unique health benefits. For example, alpha‐tocopherol (α‐VE), phytosterols, polyphenols, and flavonoids have been found in MO (Deepak & Jayadeep, 2022; Peniche‐Pavía et al., 2022; Zhou et al., 2020). Carotenoids, vitamin A precursors with strong antioxidant effects, are present in chloroplasts or other photoautotrophs, where they determine fruit seed color (He et al., 2022; Yang, Zhang, et al., 2018).…”