Preparation and evaluation of hemicellulose films and their blends

Authors: MENDES, FRANCISCO - Universidade Federal Do Ceara (UFC); BASTOS, MARIA - Embrapa; MENDES, LUANA - Universidade Estadual Do Ceara; SILVA, ANGELO - University Of Fortaleza (UNIFOR); SOUSA, FELIPE - Universidade Federal Do Ceara (UFC); MONTEIRO-MOREIRA, ANA - University Of Fortaleza (UNIFOR); Cheng, Huai; Biswas, Atanu; MOREIRA, RENATO - Universidade Federal Do Ceara (UFC)

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2017
Publication Date: 4/6/2017
Publication URL: https://handle.nal.usda.gov/10113/5667180
Citation: Mendes, F., Bastos, M., Mendes, L.G., Silva, A., Sousa, F.D., Monteiro-Moreira, A., Cheng, H.N., Biswas, A., Moreira, R.A. 2017. Preparation and evaluation of hemicellulose films and their blends. Food Hydrocolloids. 70:181-191.

Interpretive Summary: Hemicellulose is among the most common polysaccharides found in nature. It is considered a green raw material for use in food and specialty materials, e.g., as food packaging films and thickeners in food formulations. Often, however, the natural properties of hemicellulose need improvements. One way to do so is to use polymer blending. In this way, no chemical reaction is involved and the resultant blend should be cheap and safe. This article reports the extraction of hemicelluloses from two plant sources (Caesalpina pulcherrima and Tamarindus indica) and provides detailed chemical and polymer characterization of the blends. The extraction method developed in this work was shown to be feasible for obtaining the polysaccharides from seeds with yields between 20 and 30%, indicating that these sources can be exploited to obtain the polysaccharides on a large scale. The analytical results indicated that both hemicelluloses have good properties, and the films and blends formulated from these two hemicelluloses in the presence of glycerol as a plasticizer demonstrated good thermal stability. The results are important because these hemicelluloses may be useful to the food and packaging industry as feasible potential future products. These products are available, biodegradable, and sustainable.

Technical Abstract: Cell wall hemicelluloses are useful in various industries due to their ability to form edible and biodegradable films with plasticizers such as glycerol. The objective of this research was to extract hemicelluloses from Caesalpina pulcherrima and Tamarindus indica, produce film blends from them, and evaluate their properties and their product development potential. The extraction process provided yields of 25% galactomannan (GalCp) from C. pulcherrima and 20% xyloglucan (XilTi) from T. indica. The apparent Mw obtained by GPC were 4.35x10^6^ g/mol and 2.03x10^6^ g/mol for GalCp and XilTi respectively. The ratio of annose/galactose in GalCp determined by ^13^C NMR was (2: 1), while the ratio of glucose/xylose/galactose in XilTi obtained by ^13^C NMR was (1.0: 1.2: 1.0). All filmogenic solutions from these hemicelluloses showed non-Newtonian rheological behavior at 25 degreescelsius. The IR spectra were consistent with the presence of GalCp and XilTi and were fully assigned. Galactomannan film exhibited a higher permeability to moisture than xyloglucan and the blends. All films showed less than 20% opacity; thus, they were relatively transparent. Thermogravimetric analysis indicated that the blend films had good thermal stability. The use of these blends permits a wider range of properties to be obtained than the hemicelluloses alone. Thus, these materials may serve as useful biodegradable and environmentally friendly materials for food packaging applications.