Partial characterization of a plant coagulant obtained from the berries ofSolanum elaeagnifolium

Abstract

The berries of Solanum elaeagnifolium (trompillo) have been used since ancient time in Chihuahua, Mexico, as a milk coagulant in cheese making. This article describes an approach to the characterization of the plant coagulant from trompillo. From the main results, it was noticed that only the yellow berries of trompillo have proteolytic and milk-clotting activity. These activities were observed in the crude extracts (CEs) obtained from both seeds and fruit peels of yellow berries. The proteolytic activities of these CEs ranged from 6.0 to 8.5 U-Gly/mg, although the absence of NaCl in the CEs decreased their activities significantly. The milk-clotting activities of CEs from the berries of trompillo (4347-2564 MCA) were similar to those reported for other plant coagulants. Some CEs had a similar ratio of milkclotting activity/proteolysis as rennin and chymosin. This plant coagulant produced an unspecific hydrolysis on caseins, increasing the yield in fresh-type miniature cheese.Keywords: Solanum elaeagnifolium; plant coagulant; silverleaf nightshade; trompillo; fresh cheese Las bayas de Solanum elaeagnifolium (trompillo) se han utilizado por años en la elaboración de queso en Chihuahua, México. Este trabajo describe los avances en la caracterización del coagulante vegetal obtenido del trompillo. Se encontró que solo las bayas amarillas del trompillo presentaban actividad proteolítica y coagulante (en leche). Estas actividades se observaron en los extractos crudos (CE) obtenidos tanto de las semillas como de las cáscaras de los frutos amarillos. Las actividades proteolíticas de estos CEs fueron de 6.0 a 8.5 U-Gly/mg, aunque la ausencia de NaCl disminuyó significativamente su actividad. La actividad coagulante de los CEs obtenidos del trompillo (4347 a 2564 MCA) fueron similares a los reportados en otros coagulantes de plantas. Además, algunos CE presentaron un proporción de actividad coagulante/proteólisis similar al de la renina y quimosina. Finalmente, este coagulante vegetal produce una hidrólisis inespecífica en la caseína, incrementando el rendimiento en queso Fresco miniatura.

Proteolysis and Rheological Properties of Cream Cheese Made with a Plant-Derived Coagulant from Solanum elaeagnifolium

“…The mixture was cooled to room temperature and loaded in the polyacrylamide gel. The conditions of the SDS-PAGE were according to the methodology of Chavez-Garay et al [11]. The photographs of gels were digitized and analyzed with the software ImageJ (National Institutes of Health, Bethesda, MD, USA).…”

“…Milk clotting activity was estimated in both the plant coagulant and chymosin (Chy-Max, Chr Hanse, Horsholm, Denmark) according to the methodology described by Chávez-Garay et al [11]. Results were expressed as Soxhlet units of coagulation ( U ) using Equation (1).…”

“…The cream cheeses were packed in polyethylene bags and stored at 10 °C. The yields of cream cheeses were calculated with the formula described by Chávez-Garay et al [11]. All cheeses were subjected to proximate analysis using AOAC methods [15].…”

“…are used to produce a large variety of cheeses in the Mediterranean, West Africa, and southern European countries [9]. Meanwhile, plant-derived coagulants from Solanum dubium Fresen and Solanum elaeagnofolium Cavanilles are used in the manufacture of commercial cheeses in Sudan [10] and Mexico [11].…”

“…Some of the most interesting features of protease from S. elaeagnifolium is its high ratio of milk clotting activity to proteolytic activity [11]. Additionally, this plant-derived coagulant can induce the formation of stable milk-gels and curds with a soft texture, particularly at mild-acidic conditions [11,12]. In consequence, the protease from fruits of S. elaeagnifolium could be used in the manufacture of acid-enzymatic curd cheeses with a soft texture.…”