Mechanical properties of whey protein/Na alginate gel microparticles. (November 2016)

• Record Type: Journal Article
• Authors: Leon, A.M.; Medina, W.T.; Park, D.J.; Aguilera, J.M.
• Is Part Of: Journal of food engineering. Volume 188(2016:Nov.)
• Page Start: 1
• Page End: 7
• Publication Date: 2016-11
• Subjects: Whey protein -- Alginate -- Cold gelation -- Gel microparticles -- Elderly foods -- Mechanical properties -- Back extrusion; Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2016.05.005
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: A proportion of the fast-growing elderly population needs special foods which are soft to chew and easily swallowed. Gel microparticles, GMP, (e.g., less than 100 μm in size) are an alternative as texture-modifiers in liquid and pureed foods, and may be used as carriers of needed flavors and nutrients. GMP (sizes < 40 μm) were fabricated from whey protein isolate (WPI)/sodium alginate (NaAlg) mixtures by size reduction of bulk gels made by the cold-gelation method. A cell test based on back extrusion was designed to evaluate the mechanical properties of a GMP paste and image analysis techniques implemented to resolve the size of GMP. A good correlation (R 2 = 0.89) was obtained between the stress (at 60% strain) of bulk gels and that of GMP. Compression stress at 30% strain depended on the concentrations of WPI and NaAlg and a maximum was observed at intermediate values. Through Principal Component Analysis gels with low and high sodium alginate contents were clearly explaining 93% of the variability. The ample range of mechanical properties of GMP suggest that they may be used to design or modify the texture of soft foods. Highlights: Mixed gel microparticles of WPI and Na alginate were produced by cold gelation with Ca and size reduction of the bulk gels. A back extrusion test cell was designed to mechanically assess microparticles; results related well with those for bulk gels. Microparticles exhibited an ample range of mechanical properties suitable for use as texture modifiers in liquids and purees.