Dietary plant materials reduce acrylamide formation in cookie and starch-based model systems.

BACKGROUND: Dietary plant materials have attracted much attention because of their health benefits to humans. Acrylamide is found in various heated carbohydrate-rich foods. Our previous results showed that crude aqueous extracts from diverse dietary plants and some phenolic compounds could mitigate acrylamide formation in an asparagine-glucose model system. Based on our previous study, several plant materials were selected to further investigate their inhibitory effects on acrylamide formation in cookies and starch-based model systems. RESULTS: Addition of raw powders from selected dietary plants and their crude aqueous extracts could considerably reduce acrylamide formation in both cookie and potato starch-based models. Aqueous extracts of clove at 4% caused the largest reduction (50.9%) of acrylamide in cookies, whereas addition of 2% proanthocyanidins from grape seeds gave the greatest acrylamide reduction (62.2%) in a starch-based model system. CONCLUSION: It may be feasible to use some of the tested dietary plant materials to reduce acrylamide formation in cookies and other starchy foods.

Compositions of phenolic compounds, amino acids and reducing sugars in commercial potato varieties and their effects on acrylamide formation.

BACKGROUND: Potato is consumed as an important source of carbohydrate and other nutrients as well as a good source of phenolics. Acrylamide is a potential carcinogen formed during frying of potato products. This study investigated the compositions of phenolic compounds, amino acids and reducing sugars in 16 commercial potato varieties from eight countries and analysed the relationships between these compositions and the levels of acrylamide generated by heating (185 °C, 25 min) potato powders. RESULTS: Major phenolic compounds in the tested potato varieties were identified as hydroxycinnamoylquinic/hydroxycinnamoyl derivatives by liquid chromatography/mass spectrometry. Great variations in the contents of phenolic compounds, free reducing sugars and amino acids as well as wide variations in acrylamide concentration were found among the different potato varieties. Correlation analysis revealed that fructose (r = 0.956***), glucose (r = 0.826***) and asparagine (r = 0.842***) were positively correlated with acrylamide formation. Interestingly, it was observed that higher levels of phenolic compounds were related to lower levels of acrylamide (r = - 0.692*). CONCLUSION: Careful selection of potato varieties with lower levels of fructose, glucose and asparagine and higher levels of phenolic compounds may mitigate acrylamide formation during thermal processing of potato products.

Anthocyanins, hydroxycinnamic acid derivatives, and antioxidant activity in roots of different chinese purple-fleshed sweetpotato genotypes.

Anthocyanins and hydroxycinnamic acid derivatives in the crude extracts of peel, flesh, and whole roots of 10 Chinese purple-fleshed sweetpotato genotypes were simultaneously characterized by liquid chromatography-photodiode array detector-atmospheric pressure chemical ionization-mass spectrometry (LC-PDA-APCI-MS), as well as their antioxidant activities were systematically investigated and compared. Major anthocyanins were identified as peonidin or cyanidin 3-sophoroside-5-glucoside and their acylated derivatives, e.g., peonidin 3-sophoroside-5-glucoside, peonidin 3-(6''-p-feruloylsophoroside)-5-glucoside, and cyanidin 3-(6''-p-feruloylsophoroside)-5-glucoside, and main hydroxycinnamic acid derivatives were identified as mono- and dicaffeoylquinic acids (e.g., 5-O-caffeoylquinic acid and 3,5-di-O-caffeoylquinic acid) and caffeoyl-hexoside. These main phenolic compounds identified were important contributors to the total antioxidant capacity of the tested sweetpotato samples. Additionally, great variations in contents of both total and individual phenolic compounds as well as antioxidant activities between different genotypes and among various parts of the roots were observed. This study may provide value information for breeding new lines of Chinese purple-fleshed sweetpotato and also for quality control of bioactive components during production and processing.

Comparison of major phenolic constituents and in vitro antioxidant activity of diverse Kudingcha genotypes from Ilex kudingcha, Ilex cornuta, and Ligustrum robustum.

A total of seven Kudingcha genotypes from three plant species (Ilex kudingcha, Ilex cornuta, and Ligustrum robustum) with different geographic origins in China were investigated for their major phenolic compounds, individual and total phenolics contents, and in vitro antioxidant properties (ABTS, DPPH, FRAP, and OH assays). LC-PDA-APCI-MS analysis showed that Kudingcha genotypes from Ilex and Ligustrum had entirely different phenolic profiles. Major phenolics in Kudingcha genotypes from two Ilex species were mono- and dicaffeoylquinic acids, whereas those in a Kudingcha genotype from Ligustrum were phenylethanoid and monoterpenoid glycosides. All Kudingcha genotypes of Ilex exhibited significantly stronger antioxidant capacities than that of Ligustrum. Within six Ilex genotypes, great variation existed in their composition of individual phenolic compounds and their antioxidant properties. The comparative data and LC fingerprints obtained in this study may provide useful information for screening and breeding of better Kudingcha genotypes and also for their authentication and quality control.

Rapid identification of gallotannins from Chinese galls by matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry.

Chinese gall, a conventional traditional Chinese medicine, contains high levels of gallotannins. A rapid method for direct analysis of the gallotannins without using any troublesome sample pretreatments was developed using matrix-assisted laser desorption/ionization time-of-flight quadrupole ion trap mass spectrometry (MALDI-QIT-TOF MS) to successfully identify the gallotannin components in the crude extract of Chinese galls within several minutes. The high quality of the MS and MS(2) spectra acquired clearly showed that hydrolysable tannins in Chinese galls were identified as a series of the gallotannins with degrees of polymerization (DP) of 4-11 galloyl units. The MS(2) data indicated that the identified gallotannins with DP of 4-7 galloyl units had clear fragmentation with loss of 1-5 galloyl units which were further deprived of 1-3 water moieties. This technique may be used for rapid evaluation and screening of hydrolysable tannins in medicinal plants.

Characterization of estrogen-degrading bacteria isolated from an artificial sandy aquifer with ultrafiltered secondary effluent as the medium.

This study investigated the aerobic and anoxic biodegradation of four estrogens [estrone (E1), estradiol (E2), estriol (E3), and the synthetic 17 alpha-ethinylestradiol (EE2)] in microcosms constructed with marine sand and ulftrafiltered (UF) secondary effluent. Three estrogen-degrading bacteria, LHJ1, LHJ3, and CYH, were isolated. Based on gram-stain morphology and 16S rRNA sequence homology, LHJ1 and LHJ3 belong to the genus Acinetobacter and Agromyces, respectively; CYH matched to 95% with the genus Sphingomonas. Aerobically LHJ3 degrades E3, CYH degrades E1, and all three isolates oxidize E2 to E1. Under anoxic conditions, CYH degrades E1 and LHJ3 degrades E2, whereas E3 and EE2 were not degraded by the three isolates; EE2 was transformed in microcosms incubated with site ground water. The degradation kinetics of E1 and E2 by CYH and E2 by LHJ3 under aerobic conditions was linearly correlated with the initial concentration, which ranged from 50 to 2,000 microg/l. The degradation of E1 by CYH under anoxic conditions followed Michaelis-Menten kinetics. 16 alpha-Hydroxyestrone was found to be a transient transformation product of E3 under aerobic conditions.