Acrylamide in roasted barley grains: presence, correlation with colour and decrease during storage

Effects of roasting and steeping on nutrients and physiochemical compounds in organically grown naked barley teas

Barley tea, a popular beverage with cultural traditions in East Asia, has long been esteemed for its flavor, aroma, thirst-quenching properties and perceived health benefits attributed to bioactive compounds. This study investigated the nutritional, bioactive, and antioxidant aspects of three commercial naked barley varieties, focusing on the impact of roasting and subsequent steeping for tea. Roasting did not affect total dietary fiber or β-glucan content. The process reduced sugar content and led to the disappearance of free amino acids, contributing to high levels of acrylamide and color changes. Roasting diminished total phenolic compounds, particularly flavonoids, resulting in reduced antioxidant activity. Metabolite analysis identified compounds in roasted grains that could influence tea flavor and aroma. Roasted barley tea made from these varieties was not a source of dietary fiber or antioxidants, but also contained no acrylamide. Therefore, consumers seeking such benefits from barley are urged to consume whole grain foods.

Antioxidants Amelioration Is Insufficient to Prevent Acrylamide and Alpha-Solanine Synergistic Toxicity in BEAS-2B Cells

Cells produce free radicals and antioxidants when exposed to toxic compounds during cellular metabolism. However, free radicals are deleterious to lipids, proteins, and nucleic acids. Antioxidants neutralize and eliminate free radicals from cells, preventing cell damage. Therefore, the study aims to determine whether the antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) will ameliorate the maximum dose of acrylamide and alpha (α)-solanine synergistic toxic effects in exposed BEAS-2B cells. These toxic compounds are consumed worldwide by eating potato products. BEAS-2B cells were simultaneously treated with BHA 10 μM and BHT 20 μM and incubated in a 5% CO2 humidified incubator for 24 h, followed by individual or combined treatment with acrylamide (3.5 mM) and α-solanine (44 mM) for 48 h, including the controls. Cell morphology, DNA, RNA, and protein were analyzed. The antioxidants did not prevent acrylamide and α-solanine synergistic effects in exposed BEAS-2B cells. However, cell morphology was altered; polymerase chain reaction (PCR) showed reduced RNA constituents but not DNA. In addition, the toxic compounds synergistically inhibited AKT/PKB expression and its downstream genes. The study showed BHA and BHT are not protective against the synergetic toxic effects of acrylamide and α-solanine in exposed BEAS-2B cells.

Impact of different roasting conditions on chemical composition, sensory quality and physicochemical properties of waxy-barley products

Roasting improves sensory properties and differentially modulates health-related compounds of barley products.

Acrylamide in Stir-fried Potato and Onion for Simmered Dishes in Japan

Acrylamide has neurotoxicity, carcinogenicity, and genotoxicity in experimental animals and cellular systems. Fried potato is one of the major intake sources of acrylamide in food, and fried onion was reported to contain up to 100 ng/g level of acrylamide. To determine acrylamide concentration in potato and onion stir-fried prior to boiling for simmered dishes such as curry, stew, and Niku-jaga, a typical Japanese meat/potato/onion cuisine, we collected samples stir-fried at homes of volunteers who intended voluntarily to cook these simmered dishes. Acrylamide level was analyzed by GC-MS after the xanthydrol derivatization. Among 53 stir-fried potato samples, median and average values of acrylamide were found to be 2.0 ng/g and 11 ng/g, respectively. Acrylamide levels of 27 samples (51%) were less than limit of detection (LOD) (4 ng/g), and those of 13 samples (25%) were less than limit of quantification (LOQ) (10 ng/g). In cases with less than LOD and less than LOQ of acrylamide levels, one-half of LOD and average of LOD and LOQ were adopted, respectively, to calculate the median and average. This median was markedly lower than those of fried potato (180 ng/g) and potato snacks including potato chips (550 ng/g) reported in monitoring in 2013 fiscal year in Japan. Among 58 stir-fried onion samples, acrylamide level of only one sample (2%) was less than LOD (3 ng/g), and those of 15 samples (26%) were less than LOQ (8 ng/g). The median and average values in the stir-fried onion were 14 ng/g and 36 ng/g, respectively. These values are comparable to those for stir-fried onion reported by Ministry of Agriculture, Forestry and Fisheries, Japan (median 19 ng/g, average 25 ng/g). But the maximum value of stir-fried onion 420 ng/g in the present study is much higher than the reported maximum value (70 ng/g).

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

Mepiquat: A Process-Induced Byproduct in Roasted Cereal-Based Foodstuffs

Mepiquat, a growth regulator widely used in agriculture, is also known as a process-induced byproduct formed in coffee from natural constituents during heat treatments such as roasting. This study examines mepiquat formation in cereal-based foodstuffs treated at sufficiently high temperature to trigger methyl transfer reactions that involve glycine betaine and choline naturally present in cereals. Color measurements of roasted barley grains revealed a correlation between thermal treatment and mepiquat content. Trials at industrial scale on instant beverages composed of roasted cereals demonstrated significant increases in mepiquat during the thermal process (in the range of 140-205 μg/kg in final products). A targeted survey of commercial products showed mepiquat in the range 69-381 μg/kg in powdered cereal instant drinks and 42-168 μg/kg in mugicha tea, a roasted barley infusion. These findings will not significantly affect the exposure of consumers to mepiquat due to the low amounts detected.