Citrus Peel Extracts for Industrial-Scale Production of Bio-Based Active Food Packaging

Biopolymers as Sustainable and Active Packaging Materials: Fundamentals and Mechanisms of Antifungal Activities

Developing bio-based and biodegradable materials has become important to meet current market demands, government regulations, and environmental concerns. The packaging industry, particularly for food and beverages, is known to be the world's largest consumer of plastics. Therefore, the demand for sustainable alternatives in this area is needed to meet the industry's requirements. This review presents the most commonly used bio-based and biodegradable packaging materials, bio-polyesters, and polysaccharide-based polymers. At the same time, a major problem in food packaging is presented: fungal growth and, consequently, food spoilage. Different types of antifungal compounds, both natural and synthetic, are explained in terms of structure and mechanism of action. The main uses of these antifungal compounds and their degree of effectiveness are detailed. State-of-the-art studies have shown a clear trend of increasing studies on incorporating antifungals in biodegradable materials since 2000. The bibliometric networks showed studies on active packaging, biodegradable polymers, films, antimicrobial and antifungal activities, essential oils, starch and polysaccharides, nanocomposites, and nanoparticles. The combination of the development of bio-based and biodegradable materials with the ability to control fungal growth promotes both sustainability and the innovative enhancement of the packaging sector.

Red dragon fruit-soy protein isolate biofilm: UV-blocking, antioxidant & improved mechanical properties for sustainable food packaging

In this study, an active biofilm was developed by incorporating red dragon fruit peel (RDF) extract into soy protein isolate (SPI) film matrix for sustainable food packaging. The addition of betalain-rich-RDF extract (1-7 wt%) significantly improved UV-blocking and antioxidant properties of the film compared to the control film. As wt% of RDF-extract increased, water vapor permeability, water solubility, and elongation at break decreased by 1.06 × 10-10 g m m-2 s-1 Pa-1, 34.25%, and 133.25%, respectively. On the other hand, Tensile strength increased significantly (P < 0.05) by 78.76%. FTIR results confirmed the intermolecular interaction between RDF extract and SPI through hydrogen bonding, while XRD result showed a decrease in the crystallinity degree of the film with RDF extract addition. However, no significant change in the TGA curve between extract-incorporated SPI films was observed. SEM analysis revealed that SPI B and SPI D films had a more compact and denser structure than the control film, while AFM analysis showed an increase in Ra and Rq values representing higher surface roughness of SPI D film. SPI D film also significantly (P < 0.05) decreased the weight loss and increased total soluble solids of freshly cut apples over 7-day storage period.

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Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05940-2.

Development of Coated PLA Films Containing a Commercial Olive Leaf Extract for the Food Packaging Sector

A commercial olive leaf extract (OL), effective against Salmonella enterica, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus, was added to three different coating formulations (methylcellulose, MC; chitosan, CT; and alginate, ALG) to produce active polylactic acid (PLA) coated films. Evaluation of these coated PLA films revealed significant inhibition of S. aureus growth, particularly with the MC and CT formulations exhibiting the highest inhibition rates (99.7%). The coated films were then tested for food contact compatibility with three food simulants (A: 10% ethanol; B: 3% acetic acid; D2: olive oil), selected to assess their suitability for pre-cut hams and ready-to-eat vegetables in relation to overall migration. However, coated films with active functions exhibited migration values in simulants A and B above legal limits, while promising results were obtained for simulant D2, highlighting the need to deeply investigate these coatings' impact on a real food system. Untargeted metabolomics revealed that the type of coating influenced the selective release of certain phenolic classes based on the food simulant tested. The Oxitest analysis of simulant D2 demonstrated that the MC and ALG-coated PLA films slightly slowed down the oxidation of this food simulant, which is an edible vegetable oil.

The Chemical Variability, Nutraceutical Value, and Food-Industry and Cosmetic Applications of Citrus Plants: A Critical Review

Citrus fruits occupy an important position in the context of the fruit trade, considering that both fresh fruits and processed products are produced on a large scale. Citrus fruits are recognized as an essential component of the human diet, thanks to their high content of beneficial nutrients such as vitamins, minerals, terpenes, flavonoids, coumarins and dietary fibers. Among these, a wide range of positive biological activities are attributed to terpenes and flavonoids derivatives. In this review, a list of bibliographic reports (from 2015 onwards) on the phytochemical composition, beneficial effects and potential applications of citrus fruits and their by-products is systematically summarized. In detail, information regarding the nutraceutical and medicinal value closely linked to the presence of numerous bioactive metabolites and their growing use in the food industry and food packaging, also considering any technological strategies such as encapsulation to guarantee their stability over time, were evaluated. In addition, since citrus fruit, as well as its by-products, are interesting alternatives for the reformulation of natural cosmetic products, the sector of the cosmetic industry is also explored. More in-depth knowledge of the latest information in this field will contribute to future conscious use of citrus fruits.

Upgrading the physiochemical and sensory quality of yogurt by incorporating polyphenol-enriched citrus pomaces with antioxidant, antimicrobial, and antitumor activities

Industrial pomaces are cheap sources of phenolic compounds and fibers but dumping them in landfills has negative environmental and health consequences. Therefore, valorizing these wastes in the food industry as additives significantly enhances the final product. In this study, the citrus pomaces, orange pomace (OP), mandarin pomace (MP), and lemon pomace (LP) were collected by a juice company and subjected to producing polyphenols and fiber-enriched fractions, which are included in functional yogurt; the pomace powder with different levels (1, 3, and 5%) was homogenized in cooled pasteurized milk with other ingredients (sugar and starter) before processing the yogurt fermentation. The HPLC phenolic profile showed higher phenolic content in OP extract, i.e., gallic acid (1,702.65), chlorogenic acid (1,256.22), naringenin (6,450.57), catechin (1,680.65), and propyl gallate (1,120.37) ppm with massive increases over MP (1.34–37 times) and LP (1.49–5 times). The OP extract successfully scavenged 87% of DPPH with a relative increase of about 16 and 32% over LP and MP, respectively. Additionally, it inhibits 77–90% of microbial growth at 5–8 μg/mL while killing them in the 9–14 μg/mL range. Furthermore, OP extract successfully reduced 77% of human breast carcinoma. Each of pomace powder sample (OP, MP, LP) was added to yogurt at three levels; 1, 3, and 5%, while the physiochemical, sensorial, and microbial changes were monitored during 21 days of cold storage. OP yogurt had the highest pH and lowest acidity, while LP yogurt recorded the reverse. High fat and total soluble solids (TSS) content are observed in OP yogurt because of the high fiber content in OP. The pH values of all yogurt samples decreased, while acidity, fat, and TSS increased at the end of the storage period. The OP yogurts 1 and 3% scored higher in color, flavor, and structure than other samples. By measuring the microbial load of yogurt samples, the OP (1 and 3%) contributes to the growth of probiotics (Lactobacillus spp) in yogurt samples and reduces harmful microbes. Using citrus pomace as a source of polyphenols and fiber in functional foods is recommended to enhance their physiochemical and sensory quality.