Infrared heating induced improvement of certain phytobioactives, their bioaccessible contents and bioaccessibility in maize

Bioaccessibility of Tocols in Commercial Maize Hybrids Determined by an In Vitro Digestion Model for Poultry

Despite the high proportion of maize grain in animal diets, the contribution made by maize phytochemicals is neglected. Tocols and their contribution to the vitamin E content of animal diets are one example, exacerbated by sparse information on the tocol bioaccessibility of commercial hybrids. In this study, the contents of individual and total tocols and their bioaccessibility were determined in the grain samples of 103 commercial hybrids using a standardized INFOGEST digestion procedure. In the studied hybrids, total tocol content ranged from 19.24 to 54.44 µg/g of dry matter. The contents of micellar α-, γ-, δ-tocopherols, γ-tocotrienol, and total tocols correlated positively with the corresponding contents in the grain samples of the studied hybrids. In contrast, a negative correlation was observed between the bioaccessibility of γ- tocopherol, α- and γ-tocotrienol, and total tocols, along with the corresponding contents in the grain of studied hybrids. The highest bioaccessibility was exhibited by γ-tocotrienol (532.77 g/kg), followed by δ-tocopherol (529.88 g/kg), γ-tocopherol (461.76 g/kg), α-tocopherol (406.49 g/kg), and α-tocotrienol (359.07 g/kg). Overall, there are significant differences in the content and bioaccessibility of total and individual tocols among commercial maize hybrids, allowing the selection of hybrids for animal production based not only on crude chemical composition but also on the content of phytochemicals.

The zeaxanthin present in a tomato line rich in this carotenoid is as bioavailable as that present in the food sources richest in this xanthophyll

It is strongly suspected that, like lutein, zeaxanthin (ZEA) plays a biological role in the human eye. Many studies also suggest that it could reduce the risk of age-related macular degeneration and improve cognition. Unfortunately, it is only present in a very limited number of foods. This is why a new tomato line, named "Xantomato", whose fruits can synthesize this compound, was generated. However, whether ZEA in Xantomato is bioavailable enough for Xantomato to qualify as a nutritionally relevant ZEA source is not known. The objective was to compare the bioaccessibility and intestinal cell uptake efficiency of ZEA from Xantomato to that present in the richest sources of this compound. Bioaccessibility was assessed using in vitro digestions and uptake efficiency using Caco-2 cells. Xantomato ZEA bioaccessibility was not statistically different from that of common fruits and vegetables rich in this compound. Xantomato ZEA uptake efficiency (7.8%) was lower (P < 0.05) than that of orange pepper (10.6%) but not different from that of corn (6.9%). Therefore, the results of the in vitro digestion/Caco-2 cell model suggest that Xantomato ZEA could be as bioavailable as that found in common food sources of this compound.

Effects of infrared heating as an emerging thermal technology on physicochemical properties of foods

Infrared (IR) radiation is part of an electromagnetic spectrum between the ultraviolet and microwave regions. IR radiation impacts the surface of the food, generating heat that can be used as an efficient drying technique. Apart from drying, IR heating is an emerging food processing technology with applications in baking, roasting, microbial inactivation, insect control, extraction for antioxidant recovery, peeling, and blanching. Physicochemical properties such as texture, color, hardness, total phenols, and antioxidants capability of foods are essential quality attributes that affect the food quality. In this regard, the main objective of this review study was to highlight and discuss the effects of IR heating on food quality to expand its food applications and commercial adoption. The fundamental mechanisms, type of emitters, and IR processing parameters are discussed in this review to explore their impacts on food quality. Infrared heating has been shown that the appropriate operating conditions (distance, exposure time, IR power, and temperature) with high heat transfer, thus leading to a shorter drying time. Besides, IR heating used in food processing to improve food-surface color and flavor, it also enhances hardness, firmness, shrinkage, crispiness, and viscosity. Meanwhile, antioxidant activity is enhanced, and some nutrients are retained.