Alginate and pectin composite films crosslinked with Ca2+ ions: Effect of the plasticizer concentration

Abstract

a b s t r a c tThe manufacture of composite biofilms of alginate and LM-pectin crosslinked with calcium ions requires a two-step contact with Ca 2+ : initially a low-structured pre-film is formatted which is further crosslinked in a second contact with a more concentrated Ca 2+ solution containing plasticizer. This research evaluated the influence of the plasticizer (glycerol) concentration (1-15% w/v) in this finishing reticulation step on final films characteristics. The results indicated that the extent of the simultaneous Ca 2+ crosslinking and plasticization with glycerol was determined by the level of structural organization obtained in the pre-reticulation. Increasing the glycerol concentration of the crosslinking solution increased film solubility in water, moisture content, volumetric swelling and flexibility and decreased the resistance to tensile stress. Transparent alginate and pectin composite films with acceptable mechanical properties, low solubility and limited degree of swelling were obtained with 10% glycerol in the second contact solution.

Sorption and wetting properties of pectin edible films

“…An increase in water content in edible films with increased glycerol concentration has been previously observed. The increasing effect of glycerol concentration on the water content was demonstrated for whey (Oses et al 2009), soy (Cho & Rhee 2002), starch (Talja et al 2008), and carrageen (Karbowiak et al 2006) films as well for composite (alginate and pectin) films (da Silva et al 2009). Mali et al (2005) analysing the water vapour adsorption showed increasing water content values due to glycerol or sorbitol concentration.…”

“…A higher plasticiser content unfastens the polymeric structure allowing more charged sites to become accessible to water molecules. More important, glycerol itself is very hygroscopic and, therefore, probably responsible for most of the water uptake (da Silva et al 2009). For the mathematical description of the relationship between the water content in the analysed films and sorption time range an exponential equation was chosen ( Figure 2 and Table 2).…”

Scale-Up Preparation and Characterization of Collagen/Sodium Alginate Blend Films

“…As suggested by [39], usually films with higher TS values show lower values, due to the structural nature of those attributes. This result was probably induced by a certain degree of cross-linking between the proteins of collagen and SA.…”

Efeito da modificação química na solubilidade e intumescimento de microesferas à base de goma do cajueiro carboximetilada e quitosana

“…Normalmente, essa interação é feita pela inserção de moléculas bifuncionais de baixa massa molar ou íons, que promovem a formação de ligações cruzadas entre as cadeias de macromoléculas [4] . Este tipo de modificação pode ser realizado com agentes físicos, como o cálcio [5] e tripolifosfato [6,7] e agentes químicos, tais como: epicloridrina (EP) [8][9][10] , glutaraldeído (GA) [11][12][13][14][15] , N,N-metilenobisacrilamida [16] , genipina (GP) [17,18] , dentre outros.…”