Wettability of starch-gellan coatings on fruits, as affected by the incorporation of essential oil and/or surfactants

Antifungal Starch–Gellan Edible Coatings with Thyme Essential Oil for the Postharvest Preservation of Apple and Persimmon

“…As described by Marín et al [32], surfactant molecules form complexes, with the helical conformation of amylose favouring the chain aggregation and increasing the system viscosity. Likewise, this complex formation implies that a high amount of surfactant is required to enhance the spreading of the CFS on the fruit surface, as discussed by Sapper et al [29]. The increase in the SDS values for the S:G formulation with Tween 85 can be attributed to the higher solid content of the formulation, the greater viscosity that limits liquid gravitational drainage, and the lower contact angle.…”

“…The former, in turn, is affected by the wetting/spreading capacity and the viscosity of the coating formulations. In general, the SDS values were higher in apples than in persimmons, which could be related to differences in both the surface tension of the skin [29] and in the skin morphology of the fruit. Thus, persimmons are characterized by a smooth skin, where the lack of small superficial pores could limit the capillary retention of the liquid fraction.…”

“…The EO (2.5% and 5% w•w −1 ) was added to the lecithin dispersion by using a sonicator (Vibra Cell, Sonics and Materials, Inc., Newtown, CT, USA) at 20 kHz for 10 min with pulses of 1 s, as described by Valencia-Sullca et al [28]. Tween 85 was also added to S:G CFS (10 5 mg•L −1 ) in order to ensure the complete wettability of the fruit surface, according to a previous study [29], and tested on apples in a preliminary test. All the solutions were degassed using a vacuum pump (MZ 2C NT, Vacuubrand GmbH + CO KG, Germany).…”

“…This could imply problems for the extension of this coating on the apple surface. A previous study [29] reported that 10 5 mg•L −1 of Tween 85 must be added to ensure the S:G coating spreadability on the apple surface, whereas no surfactant was necessary to enhance the CFS spreadability when these contained emulsified or lecithin-encapsulated EO. Therefore, Tween 85 was added to the S:G formulation and tested in a preliminary trial with apples, in comparison with the CFS without Tween 85, in order to analyse the effect of the surfactant on the fruit quality during storage, as discussed in the next section.…”

Carvacrol encapsulation by electrospinning or solvent casting to obtain biodegradable multilayer active films for food packaging applications

“…Table 2 shows several recent studies of active materials for the preservation of different food systems, focusing on the usage of plant-derived active compounds. Whereas these are some of the successful applications of these kinds of active materials, there are also authors that report either the absence of any effect (Sapper et al 2019), or the appearance of off-flavours due to the absorption of the agent into the food matrix (Higueras et al 2014). Thus, the efficiency of the active packaging needs to be tested for the specific food matrix for which it is intended.…”