Thermal gelling properties and mechanism of porcine myofibrillar protein containing flaxseed gum at various pH values

Abstract

Flaxseed gum (FG) was reported to enhance the water holding capacity and thermal stability of myofibrillar protein (MP). However, the role of pH in the interaction of MP and FG is still unclear. The aim of this study was to evaluate gelling properties and physicochemical properties of MP-FG gel at various pH values, to explore the mechanism. The results reveal that higher pH value could increase the water holding capacity of MP-FG gels and the highest gel strength is achieved at pH 6.5. Raman spectroscopic analysis reveals that decreasing the pH from 7.5 to 5.5 induces the partial transformation of α-helices into β-sheets. At the same pH value, addition of FG also leads to the transformation of α-helices into β-sheets, affecting the formation of gel. The storage modulus (G') values and gelation rates during gelation process gradually declines with the increasing pH, which might be conducted to form a fine dense network.Las propiedades térmicas de gelificación y el mecanismo de la proteína miofibrilar porcina que contiene goma de linaza con diferentes valores pH RESUMEN Se declaró que la goma de linaza (FG) mejora la capacidad de retención del agua y la estabilidad térmica de la proteína miofibrilar (MP). Sin embargo, el papel del pH en la interacción de MP y FG aún no está claro. El objetivo de este estudio fue evaluar las propiedades de gelificación y las propiedades fisicoquímicas del gel MP-FG con diferentes valores pH para explorar su mecanismo. Los resultados revelan que un valor pH mayor podría aumentar la capacidad de retención de agua de los geles MP-FG, además la mayor fuerza del gel se consiguió con un pH 6,5. El análisis espectroscópico Raman reveló que reducir el pH de 7,5 a 5,5 induce a la transformación parcial de hélices α a láminas beta β. Con el mismo valor pH, la adición de FG también conlleva a la transformación de hélices α a láminas beta β, afectando la formación de gel. Los valores del módulo de almacenamiento (G') y el índice de gelificación durante el proceso de gelificación se reducen gradualmente con el incremento del pH, lo cual puede conducir a la formación de una densa red. ARTICLE HISTORY

The influence of flaxseed gum on the retrogradation of maize starch

“…Flaxseed gum (FG), extracted from flaxseed, has enjoyed a significant interest from food and pharmaceutical industry. Nowadays, FG draws more and more attention not only because of its excellent water‐holding capacity but also its unique gel properties (Pan et al ., ). It is reported that the concentration of FG was in positive correlation with the apparent viscosities of the starch gels; thus, it is always added into starch gels to increase the apparent viscosity (Wang et al ., ).…”

Effect of chickpea (Cicer arietinum L.) protein isolate on the heat‐induced gelation properties of pork myofibrillar protein

“…Non‐meat ingredients, especially legume proteins, are regarded as potential substitutes to improve the quality and nutritional value of meat products. This has attracted the attention of increasing numbers of scientists 5,6 …”

Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls

“…Fractionating flax seed to kernel and hull—representing 63% and 37% of the total seed weight [ 15 ], respectively—is of great importance, as it allows an oil-rich fraction (kernel) and a gum-rich fraction (hull) to be obtained, thus reducing the downstream processing cost and increasing the profitability. Numerous studies have shown interest in valorizing flaxseed hulls by extracting the residual oil [ 16 ], proteins and polyphenols [ 17 , 18 ], as well as SFG, with some potential applications [ 19 , 20 , 21 , 22 , 23 , 24 ]. Investigating other health-related benefits of SFG—such as its antioxidant potential, which has not been described before—is interesting, as it may lead to the replacement of some synthetic antioxidants, which are more and more restricted by legislation [ 25 ].…”