Development of functional active films from blend of gelatin with crude orange juice pomace pectin: Test for packaging of virgin olive oil

Abstract

The food packaging sector is focused on developing innovative materials to enhance food safety and quality while reducing environmental impact. Accordingly, this study aimed to develop packaging based on bovine gelatin (G) blended with crude sweet orange juice pomace pectin (SOPP) at different ratios (G/SOPP = 85/15, 65/35, 50/50, w/w). The obtained crude SOPP was highly methylated and exhibited antioxidant and antibacterial properties due to the presence of galacturonic acid (<70%) and phenolic compounds (58.2 ± 0.8 mg/g SOPP). High-performance liquid chromatography with diode array detection analysis revealed the presence of hesperidin, catechin, and naringin as major phenolic compounds in SOPP. Further, the incorporation of this latter improved gelatin-based packaging structural homogeneity, opacity, water vapour barrier features, glass transition temperature and tensile strength. G-SOPP (50/50) film showed efficient antibacterial activity against Escherichia coli and Bacillus subtilis and high antioxidant potential reaching values of 0.7, 48.7%, 76.7% and 68.9% for reducing power, β-carotene bleaching inhibition, DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS+ (2,2′-azinobis-[3-ethylbenzothiazoline-6-sulphonic acid]) radicals scavenging activities, respectively. Another interesting finding is that the combination of G and SOPP reduced the oil solubility of G-SOPP films suggesting great physical integrity of the film over 63 days. The polyphenol content released from G-SOPP blend film in a fatty simulant increased as SOPP content of films was increased. G-SOPP (50/50) film, designed as a pouch, delays the photooxidation process of virgin olive oil over 63 days of storage time, without altering its organoleptic properties. Overall, these outstanding results highlighted the potential use of gelatin–pectin blend films for active packaging of oils and lipid-based foods.