Effect of physical and thermal processing upon benzylglucosinolate content in tubers of the Brassicaceae maca (Lepidium meyenii) using a novel rapid analytical technique

Abstract

Benzylglucosinolate (BG) was extracted by 70% methanol from maca and purified on acidic alumina column and semi-preparative Cosmosil cholester column. The purified sample was verified as BG by electrospray ionisation mass spectrometry (ESI-MS) and nuclear magnetic resonance spectra. The purity was 98.3% as determined by HPLC-MS. BG content of maca was quantified using external standard method by HPLC. Effect of physical and thermal processing on BG content of maca was investigated. When maca was steamed for 5 min before shredding, no significant difference of BG content was observed during postshredding time, while raw maca lost 57.2% of BG in 24 h. Steamed maca showed no significant loss of BG after drying at the temperature from 20 to 80°C in 24 h. Thermal degradation was described by the first-order kinetics-Arrhenius equation for BG in the temperature range of 90-100°C.

Characteristic fingerprinting based on macamides for discrimination of maca (Lepidium meyenii) by LC/MS/MS and multivariate statistical analysis

“…Our previous work showed that the concentration of macamides was significantly different in maca treated with different drying processes, especially steaming, which led to a significant loss of macamides . In contrast, there was no significant change in benzyl isothiocyanate content when maca was treated with steam . This suggests that the accumulation of macamides in dry hypocotyls is related to benzyl isothiocyanate during the drying process.…”

“…19 In contrast, there was no significant change in benzyl isothiocyanate content when maca was treated with steam. 20 This suggests that the accumulation of macamides in dry hypocotyls is related to benzyl isothiocyanate during the drying process. Even so, macamide profiling still revealed regional differences when samples were dried in the same way.…”

“…More recently, studies have indicated that the accumulation of metabolites in maca is associated with many factors, including cultivation conditions, geographical origin, drying processes, colour type, etc . Nevertheless, how metabolites change and what factors determine their accumulation are not yet clear.…”

Preparation, characterisation and antioxidant activities of litchi (Litchi chinensis Sonn.) polysaccharides extracted by ultra‐high pressure

“…The value of 0.9172 was in line with the value of 0.8878. Generally, the lower the value of coefficient variation (CV), which illustrates the degree of precision, the higher the experiment reliability (Li et al ., ,b). In this study, the CV value (1.79%) showed that the experiments were precise and reliable.…”

“…Physicochemical properties were determined using the following methods: Molisch test (Karnpanit et al ., ), iodination reaction (Li et al ., ,b), Fehling's test, FeCl 3 reaction, ultraviolet (UV) analysis. In addition, the components of polysaccharide and proteins were determined by the phenol‐sulphuric acid method (Zhang et al ., ) and the Bradford method (Gonçalves et al ., ), respectively.…”