Polycyclic Aromatic Hydrocarbons (PAHs) and Their Importance in Animal Nutrition

Polycyclic aromatic hydrocarbons (PAHs) formed as a result of incomplete combustion of organic compounds. It contains compounds that cause toxic, teratogenic, mutagenic and carcinogenic damage, such as heterocyclic aromatic amines, benzene and formaldehyde. PAHs can be found in industrial wastes, garbage, cigarette smoke, pesticides and flue gases and can contaminate air, water, soil and food. Although more than 100 PAH compounds are detected in nature, it is accepted that 16 PAH compounds have more harmful effects. It is important to determine the PAH exposure levels of feeds used in animal nutrition, since the contamination of feed plants and factory feeds with PAH compounds will indirectly affect human health. In this study, the physical and chemical properties of PAHs and their effects on animal production and indirectly on human health were compiled.

Degradation of β-Carbolines Harman and Norharman in Edible Oils during Heating

The β-carbolines, mainly including harman and norharman, are a group of naturally occurring, plant-derived alkaloids, and are also considered as nonpolar heterocyclic aromatic amines. Sesame seed oils contain a high level of β-carbolines (harman and norharman). In China, sesame seed oil blends are one of the most popular types of vegetable oils blends, which can be used as cooking oils or frying oils. Thus, it is meaningful to investigate the degradation of β-carbolines (harman and norharman) in sesame seed oil blends as frying oils during heating. In this work, the loss of harman and norharman in different types of sesame seed oil blends have been investigated. The results showed that the degradation of harman and norharman were dependent both on the type of oil blends, heating temperature and time. Harman and norharman were more degraded during heating (150 °C, 180 °C) in oleic acid-rich oil blends compared to polyunsaturated acid-rich oil blends. Mechanistic investigation suggested that the reduction in harman and norharman in oil blends during heating was mainly due to the oxidative degradation reaction between β-carbolines and lipid oxidation products. Therefore, the contents of β-carbolines (harman and norharman) in sesame seed oil blends when used as frying oils and heated can be decreased with prolonged cooking time.