Preventing the loss of tensile, barrier and appearance properties caused by plasticiser crystallisation in whey protein films

Abstract

Whey protein films plasticised with sucrose have excellent oxygen barrier properties and high gloss that are reduced with time as sucrose crystallises. Whey protein isolate (WPI) films plasticised with sucrose were stored in 53% relative humidity for up to 60 days. The oxygen permeability, tensile properties and gloss of the films were measured periodically following ASTM (American Society for Testing Materials) methodology. Changes in properties were compared with changes in WPI films plasticised with glycerol (no crystallisation) or plasticised with sucrose (crystallisation) plus a crystallisation inhibitor. The two inhibitors studied were lactose and raffinose. Crystallisation in WPI/sucrose films decreased tensile strength and elongation at break. However, the inhibitors hindered sucrose crystallisation, and the desired film properties were maintained for a longer period of time. Raffinose was the more effective inhibitor, maintaining the film flexibility and barrier properties for over 28 days and maintaining gloss at almost 90% of the initial value for 60 days of storage.

Processing and Validation of Whey-Protein-Coated Films and Laminates at Semi-Industrial Scale as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties

“…In addition, these edible films were reported not to modify the sensory attributes of the coated good or its aspect, while providing some health benefits for the consumer [5]. A number of authors have also reported the good barrier properties of whey protein-based coating on paper [6,7], but also on plastic substrates [8][9][10][11][12]. As yet, none of these academic studies has been routed to the industry and the present study demonstrates the scale-up ability.…”

Properties and storage stability of whey protein edible film with spice powders

“…Overall results showed that mechanical properties of all film samples were enhanced during extended storage period ([7 days). Improved mechanical properties of WPI films have been reported during aging (Anker et al 2001;Dangaran and Krochta 2007) and heat curing (Amin and Ustunol 2007;Miller et al 1997). The enhanced cohesive forces in polymer films induced by gradual molecular rearrangement were hypothesized to be responsible for the stronger and less extensible film.…”

Effect of different combinations of glycerol and/or trehalose on physical and structural properties of whey protein concentrate-based edible films

“…The use of whey proteins for film formulation has been extensively reviewed, since these proteins are both edible and biodegradable, favor the reuse of cheese making effluents, and also have interesting mechanical and barrier properties (Javanmard, 2009;Ramos, Reinas, Silva, Fernandes, Cerqueira, & Pereira, 2013). Whey protein-based films mostly include food materials, which can change over time causing loss of protective functions and affecting the appearance of the covered food (Dangaran & Krochta, 2007). Therefore, the effect of storage on some film properties has been rather unexplored in most research papers.…”