Changes in contents of phenolic compounds (sinapic acid derivatives) in seeds of Brassica napus L.under adverse storage conditions [pdf]

Abstract

Background. The quality of rapeseed oil depends to a considerable degree on raw material quality. Negligence in maintaining the appropriate conditions during long-term rapeseed storage (excessively high humidity and temperature) may contribute to a deterioration of seed quality, as a result of microbial growth and changes in native antioxidant contents. The aim of this study was to investigate the effect of inappropriate storage conditions on changes in sinapic acid derivative content, which is the main phenolic compound in rapeseeds. Material and methods. The material used for tests was canola cv. PR 46 W14. Seeds with a 13.5% moisture content were stored for 21 days in a thermo-hygrostat chamber, ensuring rapeseed storage under constant humidity and temperature conditions. In this study, the level of mould fungi was analysed using the plate method, while those of sinapic acid derivatives were determined using the HPLC-DAD method. Results. Intensive growth of mould fungi in the rapeseeds was observed after 6 days of storage. Changes were recorded in sinapic acid derivative contents, which are the main phenolic compounds in rapeseed. The level of phenolic compounds found in the bound form (sinapin; sinapic acid methyl ester; 1,2-disinapoyldihexoside; 1,2-disinapoyl-hexoside and 1,2,2'-trisinapoyl-dihexoside) decreased. At the same time, an increase was recorded in trans-sinapic acid content (by 63%). Conclusion. Both qualitative and quantitative changes in phenolic compounds may be connected with the development of fungal microflora in stored rapeseeds. Only adequate storage conditions for the oil raw material, such as rapeseeds, may ensure good quality in the final product, in this case, rapeseed oil.

Genetic and Physiological Responses to Heat Stress in Brassica napus

“…Brassica seeds are rich in bioactive compounds that exhibit antioxidant action and can play a vital role in reducing blood cholesterol levels ( Ratnayake and Daun, 2004 ). In B. napus seeds, the concentrations of phytosterols can be twice that of sunflower and soybean oils ( Vlahakis and Hazebroek, 2000 ), and the content of phenolic compounds can be 10-fold greater than in seeds of other crops ( Siger et al, 2018 ). The abundance of such important biologically active compounds is sensitive to storage conditions.…”

“…As a result, the degradation of such compounds not only alters the quality of oil but can also lead to the formation of oxidized derivatives with cytotoxic properties ( Rudzińska et al, 2009 ). To investigate the effect of inappropriate storage conditions (13.5% moisture content and 25°C temperature) on seed quality in B. napus , Siger et al (2018) reported an intense growth of fungi along with a decrease in sinapic acid derivatives, the main phenolic compounds in B. napus ( Siger et al, 2018 ). The development of fungal growth not only reduces the time of safe storage but also causes a risk of seed deterioration and mycotoxin contamination posing a serious threat to human and animal health ( Siger et al, 2018 ).…”

“…To investigate the effect of inappropriate storage conditions (13.5% moisture content and 25°C temperature) on seed quality in B. napus , Siger et al (2018) reported an intense growth of fungi along with a decrease in sinapic acid derivatives, the main phenolic compounds in B. napus ( Siger et al, 2018 ). The development of fungal growth not only reduces the time of safe storage but also causes a risk of seed deterioration and mycotoxin contamination posing a serious threat to human and animal health ( Siger et al, 2018 ). Furthermore, fungal growth and respiration could also result in the production of additional heat and moisture in the seeds ( Mills, 1989 ), which further exacerbates the problem of temperature stress and microbial infestation.…”