Edible biofilm based mostly on pomegranate peel extract extends the shelf lifetime of strawberries

An edible biofilm, obtained from agricultural and fishing waste and developed by researchers on the São Carlos Institute of Chemistry of the College of São Paulo (IQSC-USP) in Brazil, permits the shelf lifetime of strawberries (Fragaria x ananassa Duch.) to be prolonged.

In laboratory assessments, the researchers discovered that over 12 days of refrigerated storage, the fruit coated with the movie misplaced 11% weight and took between 6 and eight days to start out changing into contaminated with fungi, in comparison with 4 days for fruit not lined with the fabric.

The outcomes of the work, carried out in collaboration with researchers from EMBRAPA Instrumentation and the Federal College of São Carlos (UFSCar), are revealed within the journal Meals Chemistry.

“By making use of the coating, it was attainable to double the shelf lifetime of strawberries saved underneath refrigeration and delay the dehydration of the fruit, whereas preserving the style, texture and unstable compounds that give the fruit its attribute aroma,” Mirella Romanelli Vicente Bertolo, first creator of the research and a postdoctoral researcher at EMBRAPA Instrumentation, says.

The work started throughout Bertolo’s doctoral research at IQSC-USP underneath the supervision of Professor Stanislau Bogusz Junior. Throughout their analysis, they developed a way that allowed them to extract 84.2% extra antioxidants—substances with preservative properties—from the peel of pomegranate (Punica granatum L.) utilizing pure deep eutectic solvents (NADES).

“Greater than 40% of the pomegranate, relying on the variability, is made up of peel, which is wasted. Our concept was to make use of this waste to acquire extracts wealthy in phenolic compounds with antioxidant and antimicrobial actions,” says Bogusz.

With the success of growing the extraction methodology, the researchers determined to check the speculation of incorporating the antioxidants in pomegranate into coatings based mostly on gelatin and chitosan—a polymer (pure polysaccharide) discovered within the skeletons of crustaceans resembling shrimp—to develop a protecting movie for fruit.

“We selected to make use of chitosan extracted from squid glia [inner shells] by means of a strategy of deacetylation of the chitin discovered on this mollusk, as a result of it would not have the issue of allergenicity like that obtained from shrimp. And we mixed this materials with one other polymer, on this case gelatin, to enhance its mechanical properties,” explains Bogusz.

Extremely perishable fruit

The strawberry was chosen as a mannequin system to check the effectiveness of the biofilm as a result of it is likely one of the objects with the very best loss charges in Brazilian supermarkets because of its perishability and brief shelf lifetime of about lower than seven days underneath refrigeration.

“The strawberry is a fruit that has very excessive respiratory exercise and a really low pH [acidity]. It is due to this fact very vulnerable to microbial assault. It is also very moist and the fruit is small. Based mostly on this, we hypothesized that if the fabric we developed labored, it would be efficient on every other fruit,” says Bogusz.

To check this speculation, the researchers coated strawberries with the edible movie by immersion and evaluated the results of the fabric on the physicochemical, microbiological and unstable profile and sensory traits of the fruit over 12 days of refrigerated storage.

The outcomes point out that the fabric types a movie on the floor of the fruit that acts as a barrier to the passage of microorganisms, moisture loss and gasoline alternate, modifying the strawberry’s respiration. On this method, the coating slows down the metabolism of the fruit in the course of the post-harvest interval, thereby rising its shelf life and preserving the colour, firmness and bioactive compounds of the fruit.

“We discovered that the movie made it attainable to keep up the feel, delay contamination by microorganisms and cut back the lack of fruit mass, which is noticed when the strawberry shrivels. This occurs fairly often with uncoated fruit as a result of it simply loses water and dehydrates,” says Bertolo.

Based on the researcher, the movie additionally made it attainable to scale back the severity of fungal injury and enhance the unstable profile of the fruit. “The fabric made it attainable to protect 40% extra of the compounds chargeable for the fruit’s aroma,” says Bertolo.

The biofilm additionally did not intervene with the sensory traits of the fruit, resembling taste, as confirmed by sensory evaluation assessments performed with undergraduate chemistry college students at IQSC-USP.

“The outcomes of the assessments confirmed that there have been no variations within the style, aroma or visible traits of strawberries coated with the fabric in comparison with strawberries with out the movie,” says Bertolo.

The researchers have filed a patent utility for the formulation and intend to license the expertise to firms.

Financial analyses point out that the coating may value an estimated BRL 0.15 per fruit.

“This can be a value that buyers could also be keen to pay for fruit with an extended shelf life and larger utilization,” Bertolo estimates.