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The aim of this study was to develop and characterize sodium alginate films loaded with 10-40 % Clitoria ternatea extract (CTE) and apply to monitoring the quality of milk, pork and shrimp. Films loaded with CTE showed high light barrier capacity and improved tensile strength by 3.8 times over control films. The incorporation of CTE in alginate films improved the thermal stability of the materials due to intermolecular interactions and crosslinking of polymeric networks. The addition of 40 % of CTE generated films with antibacterial action against E. coli. The alginate films showed biodegradable characteristics in soil and beach sand in 15 days. The food simulant test revealed that the loaded films show good compatibility with aqueous and acidic foods due to the release of higher levels of polyphenols and anthocyanins. The films showed great colorimetric potential due to their ability to change color at different pH (pink-green), ammonia gas (blue-green) and sterilization process (blue-yellow). When the film loaded with 40 % CTE (F40) was applied to monitor the freshness of milk and meat products (shrimp and pork), its blue color changed to purple and green, respectively. Therefore, the F40 has great potential to be used as a biodegradable indicator of freshness.

The global production of aquatic organisms has grown steadily in recent decades. This increase in production results in high volumes of by-products and waste, generally considered to be of low commercial value and part of them are consequently discarded in landfills or in the sea, causing serious environmental problems when not used. Currently, a large part of the reused aquaculture waste is destined for the feed industry. This generally undervalued waste presents an important source of bioactive compounds in its composition, such as: amino acids, carotenoids, chitin and its derivatives, fatty acids and minerals. These compounds are capable of offering numerous benefits due to their bioactive properties. However, the applicability of these compounds may be opportune in several other sectors. This review describes studies that seek to obtain and apply bioactive compounds from different sources of aquaculture waste, thus adding commercial value to these underutilized biomasses.HIGHLIGHTSVolume of aquaculture industrial waste from crustaceans and mollusks.Quantity and quality of bioactive components in aquaculture waste.Applications of recovered proteins, lipids, chitin, carotenoids and minerals.Future prospects for the destination of aquaculture waste.

A palmeira de bocaiuva (Acrocomia aculeata) é uma espécie nativa das florestas tropicais, comumente encontrada no cerrado brasileiro, onde, o interesse econômico é voltado à exploração de seus frutos. A casca da bocaiuva representa 20% da massa total do fruto e pode ser considerada como um resíduo de grande potencial alimentar devido à presença de compostos bioativos. A técnica de ultrassom é amplamente aplicada em processos de extração, de modo a reduzir o tempo e custo de extração dos compostos bioativos de matriz vegetal. O presente trabalho tem por objetivo avaliar a influência do tempo de extração dos compostos fenólicos da casca de bocaiuva aplicando a técnica assistida de ultrassom. Para isso, as cascas da bocaiuva foram secas e moídas em mesh 42, homogeneizadas em álcool etílico 50%, obtendo os extratos fenólicos a partir da exposição da mistura em um banho ultrassônico em diferentes tempos de extração (15, 30, 45 e 60 min). Os extratos foram avaliados quanto aos teores de compostos fenólicos totais e, a atividade antioxidante, determinada pelos métodos de ABTS e DPPH. Assim, foi observado que o extrato obtido em 45 min de exposição ao ultrassom apresentou maior teor de compostos fenólicos (5,46 mg EAG.g-1) e, consequentemente, atividades antioxidantes de 83,89 mg TEAC.g-1 e 99,24 mg TEAC.g-1 pelos métodos ABTS e DPPH, respectivamente. A partir dos resultados obtidos neste estudo, foi possível determinar que o tempo ideal para a extração de compostos fenólicos da casca de bocaiuva por meio do ultrassom é de 45 min. Palavras-chave: Compostos bioativos. Atividade antioxidante. Resíduo de alimentos. Biodiversidade.

A utilização de novas técnicas de extração de compostos fenólicos vem sendo estudadas no decorrer dos anos. O principal objetivo de técnicas aprimoradas de extração é a redução da utilização de solventes tóxicos e, também, promover a recuperação de biocompostos com maior agilidade e menor gasto energético. A extração por ultrassom utiliza ondas sonoras que são capazes de promover cavitações no interior de soluções, rompendo a parede de celular de diversos materiais, disponibilizando e extraindo os compostos com maior agilidade. A Clitoria ternatea (CT) é conhecida no Brasil como cunhã, flor azul, fada azul ou, então, butterfly pea, sendo comumente empregada na elaboração de chás. No entanto, esta planta apresenta atividade antioxidante, quelante de metais, antimicrobiana e anti-hiperglicêmica devido seu conteúdo de compostos fenólicos. Portanto, o presente estudo tem por objetivo obter extratos hidroalcóolicos de CT utilizando a técnica assistida por ultrassom em diferentes tempos de extração (20, 40, 60, 120 e 240 min), avaliar o conteúdo de compostos fenólicos totais e atividade antioxidante, determinando o melhor tempo de extração. A partir dos resultados obtidos foi possível verificar que dentre os tempos de extração estudados, o teor de compostos fenólicos extraídos das pétalas de CT variou entre 5,55 e 7,16 (mg g-1), sendo a melhor condição obtida no tempo de 20 min. Em relação a atividade antioxidante pelos métodos de ABTS e DPPH, foi observado que não houve diferença significativas entre os extratos obtidos, apresentando-se superior aos relatados na literatura, demonstrando grande potencial de aplicação dos extratos.

Proteins films have been developed for use in food packaging materials in order to replace synthetic polymers because of environment pollution. Despite their advantages, the use of protein films in a wide range of food products is still limited due to their hydrophilic behavior. Thus, this study aimed to decrease the sensitivity of fish protein films to water through the application of glow discharge plasma. Plasma parameters (power, pressure and time of exposure) were studied according to a 23 factorial design, and the physicochemical properties of the films including moisture content, water vapor permeability, and solubility in water were evaluated. The microstructure and thermal properties of the films were also characterized. In general, glow discharge plasma caused different effects in films properties, such as cleaning and etching which were responsible for the changes observed in physicochemical properties. Power and time of exposure, as well as their interaction, were the most influent parameters. Decrease in water vapor permeability and solubility were observed in some treatments, which are important characteristics for a material to be used as food packaging. Then, the plasma setting might be changed through the adjustment of parameters of exposure according to the specificity of the application intended.

The objective of this study was to develop, characterize and evaluate biodegradable films produced from different proteins and their blends. The proteins of hake (Cynoscion guatacupa), obtained by the process of pH variation, as well as gluten and zein proteins were used in this study. The hake protein films (HF) showed the highest tensile strength (TS) and solubility in water, while the gluten films (GF) presented the higher elongation at break comparing to the others. The blend (BL) produced with hake and gluten (BL H/G) showed higher TS, water vapor permeability and elongation (WVP), and lower water solubility than HF. BL H/G still showing good thermal properties and its biodegradability occurred in less than 10 days. The zein film presented more crystalline zones and less mechanical properties when compared to the others. The zein blends with gluten (BL Z/G) presented higher elongation and WVP, and lower solubility when compared to ZF. These changes indicate that the BL Z/G may be an alternative to improve the properties of individual zein films. The BL Z/G showed complete biodegradability in less than 40 days, while the zein films showed about 75% degraded in 60 days. The BL H/G presented good mechanical and thermal resistance, with ΔH superior to the other films, also showed complete biodegradability in less than 10 days, proving to be the most promising blend for the development of sustainable materials for food packaging.

Myofibrillar proteins have good film forming ability, that leads to the formation of polymers with interesting properties for food packaging development. However, as other bio-sourced macromolecules, they have limited performance compared to synthetic materials and cold plasma represents a promising strategy to change polymer properties. Alternating current (AC) glow discharge plasma is a novel and innovative approach for surface modification of agro-based films in order to improve their properties. Then, the effects of exposure to AC glow discharge plasma were studied on the physicochemical, microstructural and thermal properties of myofibrillar protein films from fish. Films treated for 2 min showed increased elongation at break and decreased tensile strength, while the opposite behavior was observed after 5 min of treatment. Solubility in water increased with 5 min and water vapor permeability increased with 2 min of plasma treatment. Color and opacity also increased probably as a result of chemical changes because of plasma application. Slight changes were observed in microstructure of the films. Thermal properties results agreed with the modifications observed in physicochemical performance, which might be attributed to polymer surface functionalization and etching. Thus, the AC glow discharge is a promising alternative to other strategies in order to advance properties of myofibrillar protein films for food packaging because it is a dry process, does not cause damage by heating in the material, and does not pollute the environment.

The modification of the starches aims to change the properties of these polymers making them more suitable for specific applications. Therefore, the objective of this study was to modify potato and rice starch using the hydrolysis process with hydrochloric acid (HCl) and the esterification process with citric acid (CA), both acids at different concentrations and reaction time. To verify if the modifications were effective, the physicochemical changes (solubility, swelling power, gel strength and amylose content), thermal, morphological and pasting properties were evaluated. The applied modifications reduced the swelling power, solubility and amylose content of starches. The strength of the gel was reduced with the modifications for the rice starch and increased for the potato starch. Regarding the pasting properties, modified starch RS1 (modified rice starch using 0.1 M HCl) and PS3 (modified potato starch using 2% CA) showed a tendency to reduce retrogradation. Structurally, X-ray evaluation indicated reduced crystallinity. Thermal analyses showed that gelatinization temperatures were increased for all treatments, while gelatinization enthalpies were reduced indicating greater thermal stability of the modified starches. Therefore, modified starches have distinct characteristics that can be used for specific processes that requiring starches with different properties from the conventional ones.

Active packaging produced from biodegradable polymers and essential oil could have a great value to food industries. This study aimed to evaluate the effect of the addition of oregano essential oil (OEO) on rice starch films and its application as packaging for fish fillets. Several concentrations of OEO were added to the films, the film added with 4.5% OEO showed lower permeability to water vapor 3.7 g mm kPa(−1) m(−2) day(−1), intermediate solubility of 24% and high tensile strength (4.4 MPa) while the standard film (without the addition of OEO) presented 8.8 g mm kPa(−1) m(−2) day(−1), 25.8% and 2.2 MPa, respectively. Packed fish fillets with the active film showed an increase in its shelf life when compared to the standard film. Packaged fish fillets in OEO films showed greater resistance (13.4 N), less oxidation (1.65 mg malonaldehyde/kg of sample) and less microbiological growth 10(7) CFU/g in 6 days of storage, while packaged fish fillets in standard film showed lower resistance (10.4 N), higher oxidation (1.88 mg malonaldehyde/kg of sample) and higher microbiological growth 10(8) CFU/g. Thus, the active packaging developed had the capacity to increase the shelf life of a perishable product that has great interest of food industries. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-020-04668-z) contains supplementary material, which is available to authorized users.

Conventional biosurfactants have high production costs. Therefore, the use of low-cost carbon sources for their production is attractive for industry. The ability to remain stable under various environmental conditions further extends industrial application. Here we aimed to evaluate the stability of a new lipopeptide produced by Corynebacterium aquaticum using fish residue as an unconventional energy source. The biosurfactant was produced using 3% fish residue, 2% of the microorganism, and mineral medium. Biosurfactant characterization was performed by thin layer chromatography (TLC), as well as by testing its infrared, surface tension, emulsifying activity, and ionic character. The stability of the biosurfactant was evaluated by testing its surface tension at a range of temperatures, pH, and saline concentrations, as well as after 6 months of storage. The biosurfactant was characterized as a lipopeptide due to its retention time, which was coincident with the amino acid and lipid chains obtained in the TLC analysis, being confirmed by some regions of absorption verified in the infrared analysis. The surface tension and emulsifying activity of the biosurfactant were 27.8 mN/m and 87.6%, respectively, and showed anionic character. The biosurfactant was stable at temperatures of 20 to 121 °C, in saline concentrations of 1 to 7%, and at pH close to neutrality. Based on our findings, it is possible to use unconventional sources of energy to produce a lipopeptide biosurfactant that can act under various environments.

The effect of different ratios of rice starch/fish protein (15/85, 50/50, 85/15, w/w) and different concentrations of pink pepper phenolic compounds (4%, 6% and 8%, v/w) were evaluated in films properties as well in the capacity to inhibit enzymatic browning of fresh-cut apples. The films were characterized according to mechanical properties, water vapor barrier, solubility in water, color and opacity, morphological and thermal properties. The ratio 15/85 of starch/protein showed tensile strength of 6.50 MPa and elongation at break of 173.3%. It has the greatest potential to be used as packaging for vegetables preservation. This blend showed potential to inhibit the enzyme peroxidase and thus was used as coating in fresh-cut apples. The samples coated with the blend presented lower browning index in comparison to the control sample. The blend clearly showed potential to be used as food packaging, especially to be used as antioxidant packaging to inhibit enzymatic browning.

Biosurfactants are amphipathic compounds formed by a hydrophilic and hydrophobic component, this characteristic confers to these compounds the possibility of several applications. The aim of this study was to produce biosurfactants from different industrials wastes using Corynebacterium aquaticum and Corynebacterium spp. CCT 1968 and study the application in paint removal. The production of biosurfactants was evaluated through surface tension, emulsifying activity and character ionic. The analyses were carried out at 0, 24, 48 h. The biosurfactants that presented lower surface tension and higher emulsifying activity were applied in insoluble paint. The microorganism Corynebacterium aquaticum showed efficient biosurfactant production when using fish and bagasse residues as carbon source. The surface tension obtained for these treatments was 27.8 and 33.9 mN/m and emulsifying capacity was 87.6 and 61.6%, respectively. The Corynebacterium spp. CCT 1968 produced biosurfactants only in the medium containing fish waste (28.5 mN/m). The biosurfactants produced by both microorganisms showed anionic character. The applied biosurfactants showed potential use in solubilization and paint removal. Therefore, the residues of fish and sugarcane bagasse showed efficient as carbon sources to obtain biosurfactants. In addition, the preliminary paint removal application presented great results that can be explored in the future.

The commercial use of biodegradable proteins films is still limited due to their poor mechanical and barrier performance. However, processing of proteins to modify their structure may have a significant impact on films properties. Thus, the effect of thermal or pH-induced denaturation on the gelation behavior of Withemouth Croacker proteins was investigated in the development of films for packaging. Denaturation at pH 2 and pH 10 yielded the toughest protein gels. Gelation through pH modification is related to conformational changes in the structure of fish proteins, especially in secondary structure. Rheology tests demonstrated that a stronger gel was formed at pH 2, which might be due to the positively charged proteins. This behavior is related to the lower mesh size of the gel as demonstrated by small-angle X-ray scattering experiments. Gels prepared at both pH 2 and pH 10 had the ability to form cohesive films; however, no significant differences were observed between these treatments for water vapor permeability and mechanical properties. The modification of protein structure through gelation produced more soluble and less permeable films., The authors acknowledge the financial support by the Coordination for the Improvement of Higher Education Personnel and National Counsel of Technological and Scientific Development of Brazil., info:eu-repo/semantics/publishedVersion

The purple onion peel extracts (POPE) have a high content of phenolic compounds and can be used as a promising strategy in the development of active packaging. Biodegradable sodium alginate films have good characteristics of gel formation, flexibility, transparency, brightness, and low oil permeability. The incorporation of bioactive compounds from plant residues can be a low-cost technique to functionalize alginate-based materials. The aim of this work was to evaluate the effects of POPE incorporation on the physical, mechanical, barriers, antioxidants, and antimicrobial properties of alginate-based films. Filmogenic solutions were prepared with a concentration of 0, 10, 20, and 30% of POPE and glycerol was used as plasticizer. The addition of POPE in the sodium alginate matrix promoted the development of opaque red films, with a content of phenolic compounds 43 times greater than the film without extract. As expected, the incorporation of POPE increased the antioxidant activity and the thickness of the alginate-based films. In addition, the incorporation of phenolic compounds promoted better interaction between the polymeric networks, reducing the water solubility of the alginate films. The results indicated that the sodium alginate films incorporated with several concentration of POPE have been shown to be an interesting material for the production of active packaging, being possible to apply them in foods with high water activity or susceptible to lipid oxidation, to preserve and extend the shelf life of these products.

The development of blends using sustainable raw materials promises to reach superior properties compared to biodegradable materials in general, besides the low cost and environmental appealing. This study investigates the addition of oregano essential oil (OEO) in blends from rice starch/fish protein to be used as active packaging. For this purpose, rice starch was extracted from broken grains and fish protein was recovered from Withemouth Croacker (Micropogonias furnieri). The influence of different ratios of starch/protein was confirmed by mechanical properties, solubility, water vapor permeability, opacity and color parameters. The results showed that the ratio 50/50 of starch/protein was the most suitable for packaging materials development. It had the lower solubility (8.0%), water vapor permeability (0.18 g mm kPa−1 h−1 m−2), and intermediate mechanical properties (Tensile strength 5.69 MPa, Elongation 85.5%). Morphology and thermal tests were related to the properties of the films and confirmed that the matrix was homogeneous and cohesive. The antioxidant tests confirmed the activity of the blends in inhibition of peroxidase suggesting its promising application as anti-browning packaging in fruits and vegetables. Based on the results, this research demonstrated that the use of rice starch and fish protein to form sustainable blends represents an interesting alternative for the production of active packaging and for the development of eco-friendly technologies.