RESUMEN
2-[3-(2-Thioxopyrrolidin-3-ylidene)methyl]-tryptophan (TPMT) is a yellow pigment of salted radish roots (takuan-zuke) derived from 4-methylthio-3-butenyl isothiocyanate (MTBITC), the pungent component of radish roots. Here, we prepared salted radish and analyzed the behavior of the yellow pigment and related substances in the dehydration process and long-term salting process. All salted radish samples turned yellow, and their b(*) values increased with time and temperature. The salted radish that was sun-dried and pickled at room temperature turned the brightest yellow, and the generation of TPMT was clearly confirmed. These results indicate that tissue shrinkage due to dehydration, salting temperature, and pH play important roles in the yellowing of takuan-zuke.
Asunto(s)
Isotiocianatos/metabolismo , Pigmentos Biológicos/metabolismo , Raíces de Plantas/metabolismo , Raphanus/metabolismo , Antioxidantes/química , Antioxidantes/metabolismo , Isotiocianatos/química , Pigmentos Biológicos/química , Raíces de Plantas/efectos de los fármacos , Raphanus/química , Cloruro de Sodio/química , Cloruro de Sodio/farmacologíaRESUMEN
The effects of neutralizer species on the transparency of injection-molded plates were studied using isotactic polypropylene (PP) containing a crystal nucleating agent-i.e., 1,3:2,4-bis-o-(4-methylbenzylidene)-d-sorbitol (MDBS). A plate containing lithium stearate (StLi) was more transparent than one containing calcium stearate (StCa) when the MDBS content was 0.1 wt. %. The addition of StLi accelerated the formation of MDBS fibers and the crystallization of PP. However, when the MDBS content was 1.0 wt. %, StCa improved the transparency more effectively than StLi. These results indicate that the combination of an appropriate amount of MDBS and the correct neutralizer species is critical for enhancing the transparency of injection-molded PP plates.