Impact of Biodegradable Materials on the Quality of Plums

Abstract

Edible starch-based materials have shown a positive impact on quality parameters. In this study, plums (Prunus domestica cv. Jojo) were divided into five groups: a control, two coating treatments (starch and starch-whey protein (80–20%), and two film systems (starch and starch-whey protein (80–20%). Biodegradable packaging, particularly the coating treatment, had no negative effect on color parameters. After 28 days of performed tests, firmness was boosted with starch and starch-whey protein (80–20%) films. With the coated materials, there was no significant difference compared to control group. The lowest transpiration velocity was of plums wrapped in starch films. In the case of respiration rate, no significant difference was observed between the packaging and control samples. After the conducted trials, the weight loss of untreated plums was at 10%, while 5% of weight loss was noticed for plums wrapped in starch materials, and around 6% was noticed for the other materials. Oxygen permeability was higher for S-WP films, the thickness of S and S-WP films were comparable and thickness of starch coating was around 60% higher than S-WP. Both films have an affinity to water and both show typical behavior of water vapor sensitive hydrophilic biopolymers. The starch film with the addition of 20% of proteins increased the resistance of gas exchanges, which represents one of its great benefits.

Hydroxypropyl Methylcellulose and Gum Arabic Composite Edible Coatings Amended with Geraniol to Control Postharvest Brown Rot and Maintain Quality of Cold-Stored Plums

“…The minor changes in color parameters observed in coated samples suggests a delay in ripening associated with the barrier to gases exerted by the coating emulsions and correlates with the behavior observed in the analysis of fruit firmness, with higher values in coated than in control samples, indicating that the coatings effectively modified the plum respiration and ethylene production rates and slowed down the fruit's metabolism [50]. Similar results have been reported in plums coated with HPMC [8,24], chitosan and alginate [22,46,50], GA [23], and starch/whey protein [13,16]. In addition, some studies have also confirmed that the incorporation of essential oils improves the effect of some polysaccharide coatings, such as aloe vera gel, GA, and HPMC, on delaying plum ripening parameters such as color and firmness [8,17,23,51].…”

“…Thus, for example, biopolymer-lipid composite coatings did not reduce weight loss in apples [40], cherry tomatoes [41], table grapes [42], persimmon [43], and oranges [44,45], among others. In the particular case of plums, recent works have reported the inability of coating formulations based on alginate, chitosan, starch, whey protein, pectin, and carboxy methylcellulose to create an effective moisture barrier between the fruit and the environment [13,21,22], while other works have showed a positive effect of similar biopolymer-based coatings reducing plum weight loss [20,24,46]. These works illustrate the amount and complexity of factors that affect the barrier properties of edible coatings for a particular fruit.…”

“…Although the ability of edible coatings based on starch [13][14][15][16], Aloe vera [17], chitosan [18][19][20], pectin [21], gum Arabic [22,23], carboxymethylcellulose [8,21], or hydroxypropyl methylcellulose (HPMC) [24] to reduce moisture loss and maintain texture and overall quality in plums has been documented in recent works, to our knowledge, only three studies have investigated the capacity of edible coating formulations to reduce postharvest plum decay. Thus, gum Arabic (GA) coatings containing oregano or rosemary essential oils inhibited the mycelial growth and spore germination of Rhizopus stolonifer in artificially inoculated plums [23].…”

Prunus spp. Fruit Quality and Postharvest: Today’s Challenges and Future Perspectives

“…More recently, new methodologies have emerged. The application of edible coatings of natural origin, such as proteins and polysaccharides, or the use of biodegradable materials, such as starch, has proven to be effective in improving the plum postharvest characteristics [49,52,56,57]. These coating materials are safe and without implications for human health or negative influence on the environment, allowing the preservation of fruit with good quality characteristics for a longer storage period, reduce food waste and offer consumers high-quality plums with a longer shelf-life.…”