Incorporation of polyphenols in baked products.

Bakery foods, including breads, cakes, cookies, muffins, rolls, buns, crumpets, pancakes, doughnuts, waffles, and bagels, etc., have been an important diet of humans for thousands of years. As the nutraceuticals with various biological activities, polyphenols, especially polyphenol-enriched products are widely used in bakery foods. The polyphenol-enriched products are mainly from fruits and vegetables, including fruits in whole, juice, puree, jam, and the powder of dried fruits, pomace, and peels. Incorporation of these products not only provide polyphenols, but also supply other nutrients, especially dietary fibers for bakery products. This chapter discussed the thermal stability of different types of polyphenols during baking, and the effect of polyphenols on the sensory attributes of baked foods. Moreover, their role in mitigation of reactive carbonyl species and the subsequent formation of advanced glycation end products, antioxidant and antimicrobial activities have been also discussed. Since polyphenols are subjected to high temperature for dozens of minutes during baking, future works need to focus on the chemical interactions of polyphenols and their oxidized products (quinones) with other food components, and the safety consequence of these interactions.

Identification of adducts formed between acrolein and alanine or serine in fried potato crisps and the cytotoxicity-lowering effect of acrolein in three cell lines.

In physiological and thermally-processed conditions, alanine and serine efficiently eliminate acrolein to generate two main adducts, 2-(5-formyl-3,6-dihydropyridin-1(2H)-yl) propanoic acid and 2-(5-formyl-3,6-dihydropyridin-1(2H)-yl)-3-hydroxypropanoic acid, with amounts of 81.6 ± 4.24 µg/kg and 23.72 ± 0.40 µg/kg in fried potato crisps, respectively. Adduct formation markedly decreased the cytotoxicity of acrolein against Caco-2, GES-1 and HUVEC cells. The cell viability of them remained approximately100% after incubation with 200 µmolL-1 adducts, while the IC50 values for acrolein in the three cells were 66, 54, and 16 µmolL-1 respectively. The adducts express the protective effects by tremendous reduction of cell apoptosis, reactive oxygen species (ROS) production, and DNA damage.

Isolation, structural characterization and anti-oxidant activity of a novel polysaccharide from garlic bolt.

Allium sativum L. is a widely distributed plant used as a spice, vegetable and medicine. In this study, one novel water-soluble polysaccharide (GBP-1a), with a molecular weight of 15.0 kDa, was isolated from the scape of A. sativum (garlic bolt). GBP-1a consists of galactose, glucose and arabinose at a ratio of 73.29:4.36:1.70. It has a backbone, which is composed of 1,4-linked Galp, with 1,2,6-linked Galp branches and 1-linked Glcp residue. In addition, the anti-oxidant activities of GBP-1a, as well as the two main polysaccharide fractions on ABTS radicals, metal ions and superoxide anion radicals, were evaluated in vitro. This study added new data to the study of polysaccharides from garlic bolt.

Protective effect of rosmarinic acid and carnosic acid against streptozotocin-induced oxidation, glycation, inflammation and microbiota imbalance in diabetic rats.

This study evaluated the protective effects of two rosemary components, rosmarinic acid (RA) and carnosic acid (CA), against hypoglycemia, hyperlipidemia, oxidative stress and an imbalanced gut microbiota architecture in diabetic rats. Treatment with RA and CA (30 mg kg-1) decreased the levels of fasting plasma glucose (23.7%, 15.6%), total cholesterol (30.4%, 14.1%) and triglyceride (65.7%, 47.8%) at 15 weeks. RA and CA also exhibited an anti-oxidative and anti-glycative effect by lowering the formation of malondialdehyde and advanced glycation end products. In addition, they showed protective effects against tissue damage and inflammation in the abdominal aorta, based on microscopic observations and the analysis of protein expression. Finally, the prebiotic effects of RA and CA on gut microbiota were demonstrated by increasing the population of diabetes-resistant bacteria and decreasing the amounts of diabetes-sensitive bacteria. Overall, RA showed a stronger protective effect than CA in mitigating diabetic symptoms in rats.

p-Coumaric acid and its conjugates: dietary sources, pharmacokinetic properties and biological activities.

p-Coumaric acid (4-hydroxycinnamic acid) is a phenolic acid that has low toxicity in mice (LD50 = 2850 mg kg(-1) body weight), serves as a precursor of other phenolic compounds, and exists either in free or conjugated form in plants. Conjugates of p-coumaric acid have been extensively studied in recent years due to their bioactivities. In this review, the occurrence, bioavailability and bioaccessibility of p-coumaric acid and its conjugates with mono-, oligo- and polysaccharides, alkyl alcohols, organic acids, amine and lignin are discussed. Their biological activities, including antioxidant, anti-cancer, antimicrobial, antivirus, anti-inflammatory, antiplatelet aggregation, anxiolytic, antipyretic, analgesic, and anti-arthritis activities, and their mitigatory effects against diabetes, obesity, hyperlipaemia and gout are compared. Cumulative evidence from multiple studies indicates that conjugation of p-coumaric acid greatly strengthens its biological activities; however, the high biological activity but low absorption of its conjugates remains a puzzle. © 2015 Society of Chemical Industry.