Chitosan Edible Films and Coatings with Added Bioactive Compounds: Antibacterial and Antioxidant Properties and Their Application to Food Products: A Review.

Chitosan is the deacetylated form of chitin regarded as one of the most abundant polymers and due to its properties, both chitosan alone or in combination with bioactive substances for the production of biodegradable films and coatings is gaining attention in terms of applications in the food industry. To enhance the antimicrobial and antioxidant properties of chitosan, a vast variety of plant extracts have been incorporated to meet consumer demands for more environmentally friendly and synthetic preservative-free foods. This review provides knowledge about the antioxidant and antibacterial properties of chitosan films and coatings enriched with natural extracts as well as their applications in various food products and the effects they had on them. In a nutshell, it has been demonstrated that chitosan can act as a coating or packaging material with excellent antimicrobial and antioxidant properties in addition to its biodegradability, biocompatibility, and non-toxicity. However, further research should be carried out to widen the applications of bioactive chitosan coatings to more foods and industries as well was their industrial scale-up, thus helping to minimize the use of plastic materials.

Pork Liver Pâté Enriched with Persimmon Coproducts: Effect of In Vitro Gastrointestinal Digestion on Its Fatty Acid and Polyphenol Profile Stability.

Agrofood coproducts are used to enrich meat products to reduce harmful compounds and contribute to fiber and polyphenol enrichment. Pork liver pâtés with added persimmon coproducts (3 and 6%; PR-3 and PR-6, respectively) were developed. Therefore, the aim was to study the effect of their in vitro gastrointestinal digestion on: the free and bound polyphenol profile (HPLC) and their colon-available index; the lipid oxidation (TBARs); and the stability of the fatty acid profile (GC). Furthermore, the effect of lipolysis was investigated using two pancreatins with different lipase activity. Forty-two polyphenols were detected in persimmon flour, which were revealed as a good source of bound polyphenols in pâtés, especially gallic acid (164.3 µg/g d.w. in PR-3 and 631.8 µg/g d.w. in PR-6). After gastrointestinal digestion, the colon-available index in enriched pâté ranged from 88.73 to 195.78%. The different lipase activity in the intestinal phase caused significant differences in bound polyphenols' stability, contributing to increased lipid oxidation. The fatty acids profile in pâté samples was stable, and surprisingly their PUFA content was raised. In conclusion, rich fatty foods, such as pâté, are excellent vehicles to preserve bound polyphenols, which can reach the colon intact and be metabolized by the intestinal microbiome.

Assessment of emulsion gels formulated with chestnut (Castanea sativa M.) flour and chia (Salvia hispanica L) oil as partial fat replacers in pork burger formulation.

BACKGROUND: The aim of this work was to evaluate the effect on chemical composition, physico-chemical properties, cooking characteristics, fatty acid profile, lipid oxidation, and sensory acceptability of an oil-in-water emulsion gel that was prepared with chestnut flour, chia oil, gellan gum, and water (CEG), used as a fat replacer in pork burgers. The original mixture was used as a control sample (CS). The other samples were formulated partially replacing pork backfat with 5% of CEG (CEG5%) and 10% of CEG (CEG10%). RESULTS: Proximate analysis of samples showed several differences between samples. The CEG addition was found to be effective for improving the cooking yield while diameter reduction and thickness increase were positively affected. As regards lipid oxidation, in cooked burger, the 2-thiobarbituric acid (TBA) values for CS, CEG5% and CEG10% were 0.46, 0.57, and 0.59 mg malonaldehyde/kg sample, respectively. The linolenic and linolenic acid content of pork burger increased as CEG addition increased. Sensory properties for CS and CEG5% were similar whereas CEG10% showed the highest sensory scores. CONCLUSIONS: A combination of chestnut flour and chia oil could be used as a novel ingredient to develop pork burgers with a better nutritional profile without diminishing their sensory and physico-chemical properties. © 2019 Society of Chemical Industry.

Chia Oil Extraction Coproduct as a Potential New Ingredient for the Food Industry: Chemical, Physicochemical, Techno-Functional and Antioxidant Properties.

The aim of this work was to characterize the coproduct obtained from chia oil production (cold-pressing) with a view to its possible application in new food product development. For this characterization, the following determinations were made: proximate composition, physicochemical analysis, techno-functional properties, total phenolic and flavonoid content, polyphenolic profile and antioxidant capacity (using four different methods). Chia coproduct showed significantly higher levels of proteins and total dietary fiber and lower levels of fats than chia seeds, pointing to the promising nature of this coproduct as an ingredient of food formulations since it remains a source of high biological value proteins and total dietary fiber (as chia seeds themselves) but with a lower energy value. This chia coproduct presents similar techno-functional properties to the original chia seeds and significantly higher levels of polyphenolic compounds and, consequently, higher antioxidant activity.

Evaluation of protective effect of different dietary fibers on polyphenolic profile stability of maqui berry (Aristotelia chilensis (Molina) Stuntz) during in vitro gastrointestinal digestion.

The aim of this work was to determine the protective effect of different dietary fibers on (i) the recovery and bioaccessibility indexes, and (ii) the stability of polyphenolic compounds (phenolic acids, flavonoids and anthocyanins) of maqui berry powder subjected to in vitro gastrointestinal digestion (GID). The extracts obtained in each phase (oral, gastric and intestinal) of GID were used to analyze the stability of polyphenolic compounds by HPLC, and the bioaccessibility of these compounds was also determined. At the end of the GID process, the mixture of maqui berry with the different fibers increased the bioaccessibility index of the phenolic and flavonoid compounds in all cases. The results obtained suggest that the anthocyanins and phenolic acids and flavonoid compounds present in maqui are stabilized through dietary fiber interactions, which might provide sufficient levels for absorption during gastrointestinal digestion. The gums sodium carboxymethyl cellulose, xanthan gum and guar gum provided the best protective effect.

Effect of particle size on phytochemical composition and antioxidant properties of two persimmon flours from Diospyros kaki Thunb. vars. 'Rojo Brillante' and 'Triumph' co-products.

BACKGROUND: This contribution studies the influence of the particle size of persimmon flours (from two cultivars, 'Rojo Brillante' and 'Triumph') on their primary (sugars and organic acids) and secondary (polyphenols, flavonoids and carotenoids) metabolite content, and also on their antioxidant activity, to assess whether these flours could find applications in the food industry as a potential functional ingredient. RESULTS: The main sugars were fructose and glucose and the principal organic acid was malic acid. The highest content of total phenols, flavonoids and carotenoids was found in flour fractions from cv. 'Rojo Brillante'. The phenol profile determined by HPLC identified six phenolic compounds in both persimmon flours, the most abundant being gallic acid. The greatest ABTS and DPPH radical scavenging capacity and ferric reducing power were found in flour fractions from cv. 'Rojo Brillante'. Although the influence of particle size on all these properties was not always evident, in general, the higher bioactive compound content and antioxidant capacity were in the finest particles. CONCLUSION: Co-products from cvs. 'Rojo Brillante' and 'Triumph' persimmon juice extraction can be processed to obtain flours rich in sugars, organic acids and bioactive compounds, suggesting their possible use as a functional ingredient (with antioxidant properties) in different food products. © 2017 Society of Chemical Industry.

Determination of polyphenolic profile, antioxidant activity and antibacterial properties of maqui [Aristotelia chilensis (Molina) Stuntz] a Chilean blackberry.

BACKGROUND: The aim of the present study was to determine (1) the polyphenolic profile (phenolic acids, flavonoids and anthocyanins), (2) the antioxidant using four different methodologies (DPPH, ABTS, FRAP and FIC) and (3) the antibacterial properties of maqui berry [Aristotelia chilensis (Molina) Stuntz] (MB) grown in Chile. RESULTS: The HPLC analysis of MB showed a total of 19 polyphenolic compounds identified as anthocyanins (eight compounds), flavonols (10 compounds) and ellagic acid. Delphinidin derivatives were the predominant anthocyanins while quercetin derivatives were the predominant flavonols. MB showed an antioxidant activity measured with DPPH, ABTS, FRAP and FIC methods of 28.18, 18.66, 25.22 g Trolox equivalent kg(-1) and 0.12 g ethylenediaminetetraacetic acid equivalent kg(-1) , respectively. With regard to the antibacterial activity, all strains tested were affected by MB. Aeromonas hydrophila and Listeria innocua showed the highest sensitivity to maqui berry extracts with MIC values of 40 and a 50 mg mL(-1) , respectively. CONCLUSIONS: The results suggest that maqui berry has a great potential to be employed in the food industry as potential food ingredient to functional food development or as bio-preservative. © 2016 Society of Chemical Industry.

Fig (Ficus carica) Liquid Co-Products as New Potential Functional Ingredient: Physico-Chemical and In Vitro Antioxidant Properties.

The aims of this study were to determine (i) the physico-chemical characteristics, (ii) the phenolic, flavonoid and anthocyanins profile, (iii) the organic acids and sugar content, and (iv) the antioxidant properties of the liquid co-product generated by the figs (FLC) processing industry in order to set standards for its applications as a potential ingredient of food products. The liquid co-products obtained from the peel and pulp of two fig varieties (colar and cuello de dama) were used. The polyphenolic profile and the organic acids and sugar were determined by HPLC. For the antioxidant activity, four different test systems were used (DPPH, FRAP, TBARS and FIC). The total phenolic, total flavonoid and total anthocyanin contents were also determined. The FLC from peel presented higher total phenolic, flavonoid and anthocyanin contents than FLC from pulp. The FLC obtained from peel and pulp had a high content of sugars, mainly glucose and fructose. As regards antioxidant activity, at all concentrations and with all methods, FLC obtained from peel presented higher antioxidant activity than the pulp FLC. FLC obtained from the peel and pulp could be an alternative for use as a natural preservative in food matrices due to its broad antioxidant activity.

Effects of various fibre-rich extracts on cholesterol binding capacity during in vitro digestion of pork patties.

Intake of foods containing high levels of cholesterol harms human health, and an increase in the intake of dietary fibre (DF) may mitigate these negative effects. The co-products obtained from fruit juice extraction (lemon, grapefruit and pomegranate), lemon ice-cream production and tiger nut "horchata" (beverage) have been used for the production of fibre-rich extracts used as dietary fibre sources. The purpose of this study was to examine the effect of these fibre source additions on cholesterol retention during the in vitro digestion of pork patties. The control patties were prepared without fibre addition and for the rest of patties a 10% of each DF was added. The pork patties were then passed through an in vitro digestion model that simulated the composition of the mouth, stomach and small intestine juices. After digestion and centrifugation the product separated into 3 phases (oily, aqueous and pellet phase). The effect of each DF on the phase distribution and the amount of cholesterol retained in each phase were evaluated. All DFs studied showed an increase in the cholesterol retained in the pellet phase. The pomegranate DF showed a better result (32% cholesterol retained in the pellet phase). The application of these fibre-rich extracts in food elaboration processes due to their healthy properties could be very interesting if one of the most important properties that can be highlighted is their ability to adsorb cholesterol.

Valorization of Pomace Powder Obtained from Native Mexican Apple (Malus domestica var. rayada): Chemical, Techno-functional and Antioxidant Properties.

The aims of the work were to determine the chemical, techno-functional and antioxidant properties of native Mexican apple pomace powder (MAPP) obtained from cider industry. The proximate composition and the total, insoluble and soluble dietary fibre content were determined, as well as the water holding (WHC), oil holding (OHC), swelling (SWC) capacities and the polyphenolic profile. For antioxidant activity, three different test systems were used (DPPH, FIC and FRAP). The total, insoluble and soluble dietary fiber content of MAPP was 70.91, 48.43 and 22.48 g/100 g, respectively. MAPP had a WHC, OHC and SWC of 4.2 g water/g sample, 1.69 g oil/g sample and 3.2 mL/g sample, respectively. Polyphenolic profile showed 10 flavonoid compounds identified mainly quercetin glycosides. MAPP showed good antioxidant activity with high correlation between total phenolic compounds and antioxidant capacity. The results obtained showed that MAPP could be considered a good source of bioactive compounds with significant antioxidant activity.

In vitro antioxidant and antifungal properties of essential oils obtained from aromatic herbs endemic to the southeast of Spain.

The aim of this work was to determine (i) the antioxidant capacity of Thymus moroderi, Thymus piperella, Santolina chamaecyparissus, and Sideritis angustifolia essential oils (EOs) by means of four different antioxidant tests (the 2,2'-diphenyl-1-picrylhydrazyl radical scavenging method, the ferrous ion-chelating ability assay, the ferric reducing antioxidant power test, and the thiobarbituric acid reactive species test) and (ii) the antifungal activity against molds and yeast of these EOs by the agar dilution and the microdilution methods. T. piperella EO showed the lowest 50% inhibitory concentration by the 2,2'-diphenyl-1-picrylhydrazyl radical scavenging method (9.30 mg/ml) and by the thiobarbituric acid reactive species test (6.30 mg/ml) and the highest value by the ferric reducing antioxidant power test (2.64 Trolox equivalent antioxidant capacity), while S. chamaecyparissus showed the lowest 50% inhibitory concentration in the ferrous ion-chelating ability assay (3.94 mg/ml). All EOs had a substantial inhibitory effect on all assayed yeast strains. S. angustifolia EO had the lowest MICs (2.5 µl/ml) for the yeasts Saccharomyces cerevisiae, Debaryomyces hansenii, Rhodotorula mucilaginosa, and Pichia carsonii. As regards antifungal activity, S. angustifolia EO at high concentrations was the most effective EO in reducing the growth of Alternaria alternata, Penicillium chrysogenum, and Mucor racemosus, while S. chamaecyparissus was the best inhibitor of the molds Aspergillus flavus and Mucor circinelloides. The results obtained in this study suggest the possibility of using these essential oils as natural antioxidant food preservatives.

Role of Oregano (Origanum vulgare) essential oil as a surface fungus inhibitor on fermented sausages: evaluation of its effect on microbial and physicochemical characteristics.

Oregano essential oil (OEO) was evaluated to determine its effect on the growth of natural contaminating molds on the surface of Spanish fermented sausage, the development of the internal microbial population of the sausage, and the physicochemical properties of the sausage. Results indicated a dramatic reduction in the contaminant molds. At the end of ripening, the main endogenous fungal species in control samples were Mucor racemosus (55%), Aspergillus fumigatus (20.6%), Cladosporium sphaerospermum (11.1%), Acremonium strictum (7.9%), and Aspergillus niger (4.7%). In samples treated with OEO, M. racemosus and A. fumigatus were the only species isolated; the treatment was more effective against A. fumigatus than against M. racemosus. The use of OEO to inhibit surface fungi did not affect the sausage drying process, pH, water activity, or color changes during ripening. These parameters change in a typical pattern for fermented dry-cured sausages during ripening. At the end of ripening, OEO-treated sausages had lower hardness and greater chewiness than the control but showed similar textural properties to sausages treated with potassium sorbate.

Development of combinations of chemically modified vegetable oils as pork backfat substitutes in sausages formulation.

Today's consumers look for foods which provide nutrition and pleasure, while safeguarding their health, the result of which is that they increasingly avoid foods containing cholesterol and saturated and trans fatty acids. Chemically modified vegetable oils can help tailor meat products to meet this growing need and at the same time fulfil the technological needs of the meat processing industry. In this study, 16 backfat samples were characterised for their solid fat content (SFC) and melting point and these characteristics were used to design a mixture of chemically modified vegetable oils for use as a pork fat substitute for elaborating sausages. The mixtures were prepared with different vegetable oils bearing in mind with stearic acid content due to its close correlation with the SFC. The backfat was characterised as a function of its SFC and some modified vegetable oil mixtures were proposed, which led to a 10-20% diminution in saturated fatty acids and with a melting point similar to those observed in the backfat. The fatty acid profile pointed to a polyunsaturated/saturated fatty acids ratio higher than 0.4, and an n-6/n-3 fatty acid ratio of less than 4 in both modified vegetable oil mixtures proposed.

Total phenolic content and antioxidant activity of myrtle (Myrtus communis) extracts.

The total phenolic content and antioxidant activity of methanolic, ethanolic and aqueous extracts of myrtle (Myrtus communis) leaves and berries were measured to find new potential sources of natural antioxidants. Total phenolic content was assessed by the Folin-Ciocalteau assay, while the antioxidant activity was evaluated by three methods: diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, the reducing antioxidant power assay and beta-carotene linoleic acid assay. The total phenol content of myrtle extracts ranged between 9.0 and 35.6 mg GAE per g extract. For each solvent, leaf extracts contained significantly higher amount of total phenolic compounds than berry extracts. All of the extracts presented antioxidant capacity assessed by the three methods, but at different levels depending on the concentration, the extraction solvent and the part of the plant used. Generally, leaf extracts showed higher antioxidant activities than berry extracts, while the overall antioxidant strength was in the order methanol > water > ethanol in leaf extracts and methanol > ethanol > water in berry extracts. The phenolic content exhibited a positive correlation with the antioxidant activity: DPPH assay showed the highest correlation (r = 0.949), followed by the reducing power assay (r = 0.914) and the lowest for the beta-carotene linoleic acid assay (r = 0.722).