Harman and norharman, two neuroactive β-carbolines, are present in several plants and in thermally processed foods. They exhibited a wide spectrum of biological and pharmacological effects, including antioxidant, neuroprotective, and anti-inflammatory effects. In this article, we review the progress of recent research on the presence of these compounds in food, as well as their various biological and neuroactive properties. Our findings strongly suggest that some foods, especially coffee, can act as a rich source of β-carbolines, which may possibly be associated with a reduced risk for serious neurodegenerative diseases, such as Parkinson’s and Alzheimer’s.

ABSTRACT:  This article investigates the effect of green tea extract (GTE) on biscuits lipid fraction oxidative stability. The antioxidant activity of GTE was compared with commonly used synthetic antioxidant butylated hydroxyanisole (BHA). Biscuits were prepared in 3 variations. Control samples were prepared without addition of antioxidants. The other variations were prepared by adding BHA (0.02%) and GTE at 3 different levels: 0.02%, 0.1%, and 1%. Biscuits were subjected to sensory studies and instrumental and chemical analysis. Phenolic compounds of GTE characterized powerful antioxidant activities evaluated using free radical, 2,2‐diphenyl‐1‐picrylhydrazyl method, compared with gallic acid and significantly better than BHA. Antioxidants added to the samples clearly slowed down the process of oxidation of fatty acids, inhibiting the monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) decomposition. Addition of GTE at the level of 1% gave an excellent antioxidant effect on the biscuits lipid stability, inhibiting hydroperoxides formation by about 47% to 73% compared with BHA, which showed about 16% to 60% inhibition. However, GTE did not improve significantly lipid stability, measured by anisidine value ( p ‐AV), and inhibited formation of secondary oxidation products only by 3.5%. After accelerated storage time, insensitivity of oxidized‐like flavor was about 2 times higher for control samples compared to samples with addition of antioxidants. Moreover, after storage biscuits treated with natural antioxidant received a higher panel score of overall acceptance compared to samples with BHA. Using volatile compound formation as a marker of lipid oxidation, both GTE and BHA were effective inhibitors of the decomposition of hydroperoxides.

The objective of this study was to determine the effects on quality of incorporating raspberry and cranberry pomaces into American-style muffins prepared under various baking conditions. The different baking conditions did not affect the texture or microstructure of the control muffins. The enhanced samples baked at 140 °C for 30 min were characterized by a harder texture than the control muffins and by a distributed protein matrix and distorted starch granules, while those baked at 240 °C for 15 min had a moist texture and showed incomplete starch gelatinization. The mean percent recovery of ellagic acid, flavonols, tocopherols, tocotrienols, and anthocyanins after baking were 156, 53, 48, 43, and 22 %, respectively. Lower baking temperature was better for ellagic acid and tocotrienols, but worse for flavonols, tocopherols, and anthocyanins. It seems that, for the enhanced samples, the intermediate baking conditions (180 °C for 20 min) guarantee the best microstructure and texture and the appropriate retention of phytochemicals in muffins.