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Citrus production produces about 15 million tons of by-products/waste worldwide every year. Due to their high content of bioactive compounds, several extraction techniques can be applied to obtain extracts rich in valuable compounds and further application into food applications. Distillation and solvent extraction continues to be the most used and applied extraction techniques, followed by newer techniques such as microwave-assisted extraction and pulsed electric field extraction. Although the composition of these extracts and essential oils directly depends on the edaphoclimatic conditions to which the fruit/plant was exposed, the main active compounds are D-limonene, carotenoids, and carbohydrates. Pectin, one of the most abundant carbohydrates present in Citrus peels, can be used as a biodegradable polymer to develop new food packaging, and the extracted bioactive compounds can be easily added directly or indirectly to foods to increase their shelf-life. One of the applications is their incorporation in active food packaging for microbiological and/or oxidation inhibition, prolonging foods' shelf-life and, consequently, contributing to reducing food spoilage. This review highlights some of the most used and effective extraction techniques and the application of the obtained essential oils and extracts directly or indirectly (through active packaging) to foods. [ABSTRACT FROM AUTHOR]

Active packaging is designed to interact with foods by releasing active components with biological properties, allowing the extension of foods shelf-life, being aromatic plants a source of active compounds. The main goal of this research was to develop a biodegradable whey protein based film, incorporated with an aromatic plant extract. Ethanolic extracts from rosemary and thyme were obtained from three commercial brands. The DPPH• scavenging activity assay showed that the rosemary extracts presented the highest antioxidant capacity. Thyme acetone extract had the highest antioxidant activity in the β-carotene bleaching assay. Three different mixtures of rosemary and thyme extracts with the highest antioxidant capacity showed a lower antioxidant capacity than the single extracts. The content of carnosic acid, carnosol and rosmarinic acid was determined in the three rosemary extracts, having the extract from the brand C shown the highest phenolics content. The extract showed antimicrobial activity against Staphylococcus aureus , Listeria monocytogenes and Clostridium perfringens . For the active film, 1% of the rosemary extract was incorporated into the whey protein film. The film presented antimicrobial activity against L. monocytogenes and S. aureus . [ABSTRACT FROM AUTHOR]

Since ancient times, aromatic plants have been used in food and in folk medicine. Currently, essential oils and their compounds are attracting great interest due to their proven action to preserve food quality, to extend foodś shelf-life and due to be natural. Essential oils from Ocimum basilicum (basil), Cinnamomun cassia (cinnamon), Cinnamomun zeylanicum (cinnamon) and Rosmarinus officinalis (rosemary) were analyzed by Gas Chromatography coupled with Flame Ionization Detector and with Mass Spectroscopy and by Ultra High Performance Liquid Chromatography with a Diode Array Detector. The antimicrobial activity against Escherichia coli , Staphylococcus aureus and Penicillium spp and antioxidant activities by FRAP, DPPH , ABTS + and β-carotene bleaching assays were evaluated. C. cassia essential oils presented a strong antimicrobial activity, with a range of minimum inhibitory concentrations between 0.04–0.07 mg mL −1 , depending on the microorganism tested. The main compound of C. cassia essential oil, cinnamaldehyde, showed antimicrobial effectiveness. In general, C. zeylanicum essential oil and its major compound, eugenol, presented the highest antioxidant activity. Ultra High Performance Liquid Chromatography confirmed the results of the essential oils main constituents, analyzed firstly by Gas Chromatography. Ultra High Performance Liquid Chromatography technique showed to be a valuable alternative tool for the identification and quantification of the major compounds of essential oils, especially when these are incorporated into food packaging and there is the need of carrying out migration studies in food or food simulants. Cinnamon essential oils exhibited the highest biological activity directly related to its major compounds, eugenol and cinnamaldehyde. Essential oils showed to have high antioxidant and antimicrobial activity and therefore, they have great potential as natural additives of food packaging. [ABSTRACT FROM AUTHOR]

Background Essential oils (EOs) extracted from plants have been the focus of numerous researches due to their potential in the food and pharmaceutical industries and aromatherapy. Scope and approach The effectiveness of EO may be observed in antimicrobial and antioxidant tests. Volatile compounds are present in EOs and are responsible by their biological activities, namely antimicrobial and antioxidant capacity. Several manuscripts and patents have emerged with applications of EOs and their constituents, and their incorporation into food packaging. These packages with EOs have shown efficiency against microorganisms and oxidants in vitro, in tests with food and/or food simulants evaluation tests. In line with this, chromatographic techniques can be used to identify the main volatile compounds present in EOs or to determine the compounds that migrated from packaging to food or food simulants. This review provides a concise and critical insight in the use of EOs with emphasis in food applications. The innovative food packaging applications are highlighted and future trends are discussed. Key findings and conclusions In general, EOs extend food stability during storage, inhibiting the growth of spoilage or pathogenic microorganisms and protecting against oxidation. Moreover, in spite of the potential of EOs, more studies should evaluate their safety and possible side effects before considering their use for food purposes. [ABSTRACT FROM AUTHOR]

Active packaging aims to prolong food's shelf-life by directly interacting with the packaged food. This type of packaging is characterized by having the active agent incorporated into the package polymer, such as antioxidant additives, that will gradually migrate from the package polymer to the packed food and, consequently, delay food's natural lipid oxidation. In this study, the efficiency of an active whey protein film incorporated with a rosemary extract on retarding the lipid oxidation of salami slices was evaluated. The lipid oxidation of the salami was measured by the thiobarbituric acid reactive substances (TBARS) assay and hexanal monitorization. Also, a sensory analysis on the salami packaged for 60 and 90 days was performed. The active film was able to delay the salami's lipid oxidation for, at least, 30 days. The samples packaged with the active film revealed a bitter taste related to the rosemary extract and a bit sweet from the WP and the glycerol. [ABSTRACT FROM AUTHOR]

Active packaging is becoming progressively more significant as a response to the dynamic changes in current consumer demand and market tendencies. Active packaging is projected to interact directly with the packaged food or with the headspace within the package with the aim of maintaining or extending product quality and shelf-life. Aiming for sustainability, the potential application as biodegradable films of whey protein concentrate (WPC) was evaluated. Aromatic plant's extracts present high antioxidant properties, representing an alternative for synthetic food additives. The main objective of this study was to verify the effectiveness of an edible WPC film incorporated with a plant-based extract on retarding the lipid oxidation of fresh salmon. Green tea extract (GTE) was chosen to be incorporated into the active film. Fresh salmon was packaged with the control film (WPC) and with active film (WPC–GTE). The oxidation level of non-packaged samples and packaged samples were tested for different storage times. Four methods were applied to evaluate lipid oxidation state of fresh salmon: peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) assay, and monitoring of hexanal. The results obtained in this study indicate that the whey protein active film was successfully produced, and it was effective in delaying lipid oxidation of fresh salmon samples until the 14th day of storage. [ABSTRACT FROM AUTHOR]

This study focused on the recovery of antioxidant compounds from lemon and tomato by-products for use as natural additives in the development of active food packaging formulated using three different polymeric matrices that included low-density polyethylene (LDPE), polylactic acid (PLA), and G-polymer (GP). The films were characterized according to chemical-physical, thermal analyses, and their barrier and mechanical properties. Migration assays were performed to evaluate the release of active compounds from polymeric matrices, which were quantified in the food simulant by high-performance liquid chromatography with a diode array detector and then confirmed via liquid chromatography coupled to mass spectrometry. The antioxidant capacities of the films were determined to evaluate their applicability for use as antioxidant-active packaging. The incorporation of extracts into polymers resulted in different structural changes and enhanced properties according to the nature of the polymeric matrix based on the interactions of the –OH groups of polyphenols and the chemical groups of the polymers. The lemon (LE) and tomato (TE) extracts lead to a substantial improvement in water barrier properties of PLA and GP-based films. The active PLA and GP films released high amounts of polyphenolic compounds (up to 65% for GP containing LE); mainly hesperidin and eriocitrin for LE films, and chrologenic acid for TE films. PLA loaded with lemon extract at 4% was selected as the most suitable for use as antioxidant packaging to extend the shelf-life of foods with high fat content. • Active films were developed using lemon (LE) and tomato (TE) by-product extracts. • LE and TE incorporation lead to significant structural changes in the active films. • TE significantly improved the hydrophobicity of the LDPE polymer. • GP and PLA films exhibited good release properties for active compounds. • PLA active films are rich in polyphenols and displayed the best antioxidant properties. [ABSTRACT FROM AUTHOR]