Edible coatings enriched with ultrasound-assisted Arabica coffee pulp nanoextract (Coffea arabica L.) for extending shrimp and strawberry shelf life

Arabica coffee pulp is known to contain fiber and bioactive compounds that are antimicrobial, so it has the potential to be used in edible film formulations and edible coating applications to increase the shelf life of food products. However, conventional extract incorporation often results in large particle aggregation and reduced functional release. This work aimed to develop and optimize edible film formulations by adding Arabica coffee pulp using Response Surface Methodology (RSM), develop it through ultrasonication to overcome these limitations, and assess its effectiveness on the shelf life of shrimp and strawberries. The concentrations of sodium alginate (ALG) (1% to 2% w/v) and Arabica coffee pulp extract (CPE) (10% to 20% v/v) were considered independent variables. The variable combinations for the optimal response function were 1% (w/v) ALG and 20% (v/v) CPE. The validated optimum formula was further developed using ultrasonication which successfully reduced particle size to 31 nm and significantly improved of the film’s mechanical strength and barrier properties, leading to an increase in tensile strength (TS) by 78% and elongation at break (EAB) by 17.75%, along with decreases in thickness (18.81%), water vapor transmission rate (WVTR) (33.36%), and solubility (10.11%). Furthermore, the nano coffee pulp extract (NCPE) film exhibited higher antimicrobial activity against Escherichia coli and Staphylococcus aureus compared to the coffee pulp extract (CPE) film. Applied as a coating, the NCPE was able to reduce the rate of weight loss in shrimp by 4.01% and strawberries by 11.09%, and significantly suppressed microbial growth, achieving approximately 99% reduction in shrimp, maintaining the texture value of food products, and extending the shelf life of shrimp for 36 hours and strawberries for 5 days at room temperature. Thus, the development of edible film and edible coating through the addition of Arabica coffee pulp nano extract has proven effective in improving physical characteristics and antimicrobial activity.