Physicochemical and chemosensory properties of pomegranate (Punica granatum L.) seeds under various oven-roasting conditions.

This study investigated the effects of oven-roasting temperature (160, 180, and 200 â„ƒ) and time (5, 10, 15, and 20 min) on pomegranate seeds. Physicochemical properties, such as color (L*, a*, and b* values), browning index (BI), total phenolic and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, and chemosensory properties, including taste and volatile compounds, were analyzed. The L* and a* values, and level of sourness, umami, sweetness, and terpenes decreased, whereas the b* value, BI, and level of saltiness, bitterness, furan derivatives, pyrazines, and sulfur-containing compounds, increased with roasting time. The findings of this study showed that the positive roasting conditions for pomegranate seeds were 10-20 min at 160 â„ƒ and, 5-10 min at 180 â„ƒ. This study is expected to be used as a primary reference for selecting the optimal oven-roasting conditions in which positive effects appear and for developing products utilizing pomegranate seeds.

The level variation of Nε-(carboxymethyl)lysine is correlated with chlorogenic acids in Arabica L. Coffee beans under different process conditions.

Nε-(carboxymethyl) lysine (CML) is universally used as a marker of the occurrence of advanced glycation end products (AGEs) in foods. This study investigated the level changes of CML, chlorogenic acids (CQAs), lysine (Lys), fat and pH in coffee during roasting. The CML level went up slowly in the first 10 mins, then declined sharply during the next 2 mins, and kept increasing constantly in the following baking time, while the lowest CML level was obtained by roasting at 235 °C for 12 mins. The three CQAs isomers had different efficacy in affecting the levels of CML and other factors, indicating the CQAs isomers may play an important role in influencing the CML level. So it might be possible to regulate the formation of CML and gain better coffee quality via adjusting the levels of CQAs in baking process. This study provided important enlightenment on CML control during coffee baking.

Study on formation of nitrated polycyclic aromatic hydrocarbons from different roasting condition in coffee.

Nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) are organic, carcinogenic and mutagenic compounds that originate from the reaction of PAHs with NOx and OH radicals. In this study, an analytical method was developed, for the determination of seven nitro-PAHs and the method was applied to quantify the nitro-PAHs, in coffee model systems, prepared with coffee beans produced from three distinct locations and under various roasting conditions. Also, experiments were performed to study the effect of adding various amino acids on the formation of nitro-PAHs. The free radicals produced, were quantified by electron spin resonance (ESR), to assess their correlation with the formed nitro-PAHs. After extraction and cleanup, the nitro-PAHs in coffee were analyzed by gas chromatography/mass selective detection. In all heated coffee model systems, the addition of the amino acids, significantly increased the nitro-PAHs compared to the control. The ESR results were consistent with previous outcomes on the formation of nitro-PAHs.

Changes in the functional components and radical scavenging activity of maize under various roasting conditions.

The phenolic compounds and radical scavenging activity of ethanolic extracts from maize at various roasting conditions were evaluated in this research. The free sugar contents in roasted maize significantly decreased with higher roasting temperature and longer roasting time. The total polyphenol and total flavonoid contents in roasted maize significantly increased with higher roasting temperature and longer roasting time. The predominant phenolic acid in the roasted maize was homogentisic acid. The contents of homogentisic acid and myricetin in roasted maize significantly increased with higher roasting temperature and longer roasting time. The DPPH and ABTS radical scavenging activities of roasted maize significantly increased with higher roasting temperature and longer roasting time. DPPH and ABTS radical scavenging activities were positively correlated with phenolic compounds. The activities of these components increased following heat treatments because of the low molecularization effects of the heating process, which resulted in active, low-molecular-weight components that were readily extracted.

Antioxidant and neuronal cell protective effects of columbia arabica coffee with different roasting conditions.

In vitro antioxidant activities and neuronal cell protective effects of ethanol extract from roasted coffee beans were investigated. Colombia arabica coffee (Coffea arabica) green beans were roasted to give medium (230°C, 10 min), city (230°C, 12 min) and french (230°C, 15 min) coffee beans. Total phenolics in raw green beans, medium, city and french-roasted beans were 8.81±0.05, 9.77±0.03, 9.92±0.04 and 7.76±0.01 mg of GAE/g, respectively. The content of 5-O-caffeoylquinic acid, the predominant phenolic, was detected higher in medium-roasted beans than others. In addition, we found that extracts from medium-roasted beans particularly showed the highest in vitro antioxidant activity on ABTS radical scavenging activity and FRAP assays. To determine cell viability using the MTT assay, extracts from medium-roasted beans showed higher protection against H2O2-induced neurotoxicity than others. Lactate dehydrogenase (LDH) leakage was also inhibited by the extracts due to prevention of lipid peroxidation using the malondialdehyde (MDA) assay from mouse whole brain homogenates. These data suggest that the medium-roasting condition to making tasty coffee from Columbia arabica green beans may be more helpful to human health by providing the most physiological phenolics, including 5-O-caffeoylquinic acids.