洋葱皮提取物对西式香肠抗氧化及品质的影响

通过测定酸价、过氧化值与硫代巴比妥酸值来监测西式香肠在储存过程中的脂肪氧化程度的变化,并采用色差、全质构分析等方法将洋葱皮提取物香肠与空白对照样品的品质进行比较,以考察洋葱皮提取物对西式香肠的色泽、质构以及氧化稳定性的影响。结果显示:洋葱皮提取物的添加量为0.5%时,不仅抑制了西式香肠脂肪的氧化,而且还改善了其色泽,降低了其硬度、弹性与咀嚼性。     

Soy protein – Poly (lactic acid) bilayer films as biodegradable material for active food packaging

The preparation and characterization of biodegradable bilayer films from isolated soy protein (SPI) and poly (lactic acid) (PLA) were carried out in this work. The films showed high transparency and strong adhesion between layers without adding an extra component, or without chemically modifying the film surfaces. The application of the PLA layer largely increased the mechanical properties of the films with respect to those of pure SPI films. Furthermore, the hydrophobic characteristics of the PLA layer improved film performance under conditions in which water was involved, markedly decreasing the amount of total soluble matter, the swelling index and the water vapor permeability. The biodegradation under soil burial conditions was evaluated measuring weight loss as a function of time, showing a two-step degradation and a faster degradation rate for the protein component compared to those of PLA layer. The films prepared were evaluated as active packaging by incorporation of an antifungal and an antibacterial agent (natamycin and thymol, respectively) to the SPI layer, showing a marked growth inhibition of mold, yeast and two strains of bacteria by in-vitro microbiological assays.     

南瓜皮黄色素的提取工艺及其抗氧化性的研究

以南瓜皮为原料,采用超声波辅助溶剂提取南瓜皮黄色素。实验结果表明,以丙酮-石油醚为提取剂,在超声波功率为150W时,最佳提取温度为30℃,最佳提取时间为40min,最佳提取料液比为1∶10。南瓜皮黄色素具有抗氧化作用,一定浓度范围内可以清除超氧阴离子自由基、羟基自由基,抑制猪油氧化,同时VC具有协同抗氧化的作用。     

含石榴皮提取物的活性薄膜在猪肉保鲜中的应用研究

以1.5%的石榴皮提取物(pomegranate peel extract,PPE)为抑菌剂,以聚乙烯树脂(PE)和聚丙烯树脂(PP)为基材制备出PE、PPE—PE、PP/PPE—PE活性薄膜;分别考察3种薄膜的抗张强度、透光率、雾度、透氧率等基本性能;以3种薄膜分别包装新鲜猪肉,置于(4±1)℃条件下进行冷藏保鲜,期间每2d测定样品的汁液流失率、感官品质、细菌菌落总数(total viable counts,TVC)、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、pH值、硫代巴比妥酸值(thiobarbituric acid reactive substance,TBA value),并对不同薄膜的保鲜效果进行评价。PPE—PE薄膜的氧气透过量为PE薄膜的1.96倍,PP/PPE—PE薄膜的4倍;PPE的加入导致PPE—PE活性薄膜的透光率下降,雾度和抗张强度上升。在第6天,对照组(PE组)猪肉样品的菌落总数从3.54lg(CFU/g)上升至6.54lg(CFU/g),而PP/PPE—PE和PPE—PE组猪肉样品的菌落总数在第8天超过6lg(CFU/g)。结果表明:相对于PE薄膜,PP/PPE—PE和PPE—PE活性薄膜能延长猪肉货架期2~3d,PP/PPE—PE活性薄膜的综合保鲜效果优于PPE—PE活性薄膜。     

绿茶、洋葱皮水提物对面团粉质特性、面条保鲜效果、蒸煮特性及抗氧化性能的影响

本研究以小麦粉,绿茶、洋葱皮水提物为原料制作生鲜面,对面团的粉质特性、面筋指数、蒸煮特性及生物活性等进行测定。结果表明,与对照组相比,绿茶、洋葱皮的水提物的添加,导致面团稳定时间分别下降了49.5%和60%,面筋指数分别下降7.1%和17.1%。植物水提物的添加致使面条的蒸煮损失和断条率增加了约2%和15%。同时,添加绿茶、洋葱皮水提物面条的总酚含量以及抗氧化能力均明显高于对照组,而且在一定程度上抑制微生物的生长繁殖,延长产品货架期。     

Physical performance of biodegradable films intended for antimicrobial food packaging

Antimicrobial films were prepared by including enterocins to alginate, polyvinyl alcohol (PVOH), and zein films. The physical performance of the films was assessed by measuring color, microstructure (SEM), water vapor permeability (WVP), and tensile properties. All studied biopolymers showed poor WVP and limited tensile properties. PVOH showed the best performance exhibiting the lowest WVP values, higher tensile properties, and flexibility among studied biopolymers. SEM of antimicrobial films showed increased presence of voids and pores as a consequence of enterocin addition. However, changes in microstructure did not disturb WVP of films. Moreover, enterocin-containing films showed slight improvement compared to control films. Addition of enterocins to PVOH films had a plasticizing effect, by reducing its tensile strength and increasing the strain at break. The presence of enterocins had an important effect on tensile properties of zein films by significantly reducing its brittleness. Addition of enterocins, thus, proved not to disturb the physical performance of studied biopolymers. Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste. Practical Application: Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste.     

Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents

Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.     

Active/smart carboxymethyl cellulose-polyvinyl alcohol composite films containing rose petal extract for fish packaging

In this study, a film was developed for packaging fish that not only enhanced its shelf life but also was visually receptive to its spoilage. Rose petal extract (RPE) having excellent bioactivity was used as the functional component in carboxymethyl cellulose-poly vinyl alcohol packaging film. Due to its high anthocyanin content, RPE could be used as a pH indicator, as its colour changed from bright red (pH 2) to yellow (pH 10). The developed film was used for packing Indian Mackerel and assessing its quality during chilled storage. Mackerel packed in neat film spoiled in 3 days while that in RPE containing films had shelf life of 12 days. Total bacterial count, pH, total volatile basic nitrogen and thiobarbituric acid reactive substance of fish in control were higher as compared to in RPE films. On spoilage RPE containing films showed visible colour response from red to green.     

Physical,antimicrobial and antioxidant properties of starch‐based film containing ethanolic propolis extract

Propolis is a natural product that meets the requirements as functional additive for food packaging due to its antioxidant and antimicrobial activities. In this work, ethanolic propolis extract (EPE) was incorporated in cassava starch films, and characterisations with respect to their microstructure, mechanical properties, water vapour permeability (WVP), moisture sorption kinetics as well as antimicrobial and antioxidant capacities were performed. The results showed that tensile strength was not affected (P > 0.05) by the presence of EPE but Young's modulus decreased about 50% when compared to control films possibly because of EPE plasticiser effect. When 1% EPE was used, changes in moisture sorption properties were detected by a slightly hydrophobic character at films WVP. When extracted from the films, propolis retained its antioxidant activity. The films exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli even at low EPE concentrations (0.5%) mainly due to its phenolic compounds.     

Active chitosan–chestnut extract films used for packaging and storage of fresh pasta

A tannins-rich chestnut extract was used to enhance the antioxidant and antibacterial properties of chitosan-based film materials. The favourable mechanical properties of the novel material enabled its application in the preparation of the sachets that were used for packing and storage of filled fresh pasta. The fresh pasta ageing progressed in conventional refrigerated storage conditions of 8 °C with 60 ± 2% relative humidity in the absence of light for 60 days. The rapid moisture mobility between a starchy food and sachets during the first 9 days of storage induced retrogradation of the fresh pasta, whereby total phenolic content show dependency on moisture throughout the shelf life. Active components within the sachet prevented microbial growth on the food surface during the entire 60 days.     

Effect of an active packaging with citrus extract on lipid oxidation and sensory quality of cooked turkey meat

An antioxidant active packaging was prepared by coating a citrus extract, consisting of a mixture of carboxylic acids and flavanones, on polyethylene terephthalate trays. The effect of the packaging in reducing lipid oxidation in cooked turkey meat and on meat pH, colour characteristics and sensorial parameters was investigated. An untrained sensory panel evaluated the odour, taste, tenderness, juiciness and overall acceptability of the meat, using triangle, paired preference and quantitative response scale tests. A comparison between the antioxidant effects of the different components of the extract was also carried out. The packaging led to a significant reduction in lipid oxidation. After 2 days of refrigerated storage the sensory panel detected differences in odour and, after 4 days, rated the meat stored in the active packaging higher for tenderness and overall acceptability. Citric acid appeared to be the most important component of the extract with regard to its antioxidant potency.     

Extension of the display life of lamb with an antioxidant active packaging

Fresh lamb steaks were treated with three different preparations of natural antioxidants: one group was packaged with a rosemary active film, the second group was packaged with an oregano active film, and the third group was sprayed on the meat surface with a rosemary extract before packaging in a high-oxygen atmosphere. Samples were stored under illumination at 1 ± 1 °C for 13 days. Metmyoglobin formation, lipid oxidation (TBARS), instrumental colour (CIE a^*), psychrotrophic bacterial counts (PCA), sensory discolouration and off-odour were determined. The use of a rosemary extract, a rosemary active film or an oregano active film resulted in enhanced oxidative stability of lamb steaks. Active films with oregano were significantly more efficient than those with rosemary, exerting an effect similar to that of direct addition of the rosemary extract; in fact, they extended fresh odour and colour from 8 to 13 days compared to the control.     

柚子皮提取物安全性评价及其多糖分子量分布

目的 评价柚子皮提取物的食用安全性,并测定其中所含多糖的分子量分布。方法 采用最大耐受剂量法,以35.45 g/kg的剂量灌胃实验小鼠,评价柚子皮提取物的急性毒性,采用鼠伤寒沙门氏菌回复突变实验(Ames实验)和骨髓细胞微核实验评价其致突变性。采用凝胶渗透色谱法测定柚皮多糖的分子量分布。结果 小鼠无明显中毒症状和死亡。Ames实验结果显示柚子皮提取物为诱变阴性。鼠骨髓细胞微核实验3个剂量组的微核发生率与阴性对照组比较无显著性差异,表明柚子皮提取物无毒,其在实验条件下无致突变性。提取物中3种粗多糖的分子量有显著差异,且所用乙醇浓度越低,被沉淀多糖的分子量越大。结论 柚子皮提取物无毒,具有较高的食用安全性,提取物中多糖的分子量差异显著。     

Development of an active food packaging system with antioxidant properties based on green tea extract

A formula including green tea extract (GTE) was developed as an active food packaging material. This formula was moulded to obtain an independent component/device with antioxidant properties that could be easily coupled to industrial degassing valves for food packaging in special cases. GTE components (i.e., gallic acid, catechins and caffeine) were identified and quantified by HPLC-UV and UPLC-MS and migration/diffusion studies were carried out. Antioxidant properties of the formula alone and formula-valve were measured with static and dynamic methods. The results showed that the antioxidant capacity (scavenging of free radicals) of the new GTE formula was 40% higher than the non-active system (blank). This antioxidant activity increased in parallel with the GTE concentration. The functional properties of the industrial target valve (e.g., flexibility) were studied for different mixtures of GTE, and good results were found with 17% (w/w) of GTE. This new active formula can be an important addition for active packaging applications in the food packaging industry, with oxidative species-scavenging capacity, thus improving the safety and quality for the consumer and extending the shelf-life of the packaged food.     

柑橘皮提取液对银鱼保鲜作用的研究*

通过对银鱼的pH值、挥发性盐基氮、硫代巴比妥酸值和细菌菌落总数等检测指标定期取样测定,研究了柑橘皮提取液在4℃条件下对银鱼的保鲜效果。试验结果表明,柑橘皮提取液能够有效地延缓相关指标的升高,具有良好的保鲜作用,为柑橘皮提取液在银鱼储藏保鲜方面的实际应用提供了一种新方法。     

Physical properties and antioxidant activity of an active film from chitosan incorporated with green tea extract

An active film from chitosan incorporated with aqueous green tea extract (GTE) was developed. The effects of GTE concentrations including 2, 5, 10 and 20% (w/v) of green tea in the film-forming solution on the film properties were determined by measuring physical properties, total polyphenolic content and antioxidant activity of the active films. Fourier Transform Infrared (FTIR) spectrometry was carried out to observe the potential modifications of the chitosan films when incorporated with GTE. The results suggested that incorporation of GTE into chitosan films improved mechanical and water vapor barrier properties and enhanced polyphenolic content and antioxidant activity of the films. Changes in the FTIR spectra of the chitosan films were observed when GTE was incorporated, suggesting some interactions occurred between chitosan and the polyphenols from GTE. This study showed the benefits of incorporation of GTE into chitosan films and the potential for using the developed film as an active packaging.     

Improving the functionality of biodegradable food packaging materials via porous nanomaterials

Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste.     

Display life of beef packaged with an antioxidant active film as a function of the concentration of oregano extract

Fresh beef steaks were packaged with a new antioxidant active system containing increasing concentrations (0.5, 1, 2 and 4%) of an oregano extract. Control samples were packaged without the active film. Additional samples were sprayed with the extract and packaged as the control samples. Packages were filled with a 80%O(2)/20%CO(2) atmosphere and displayed under illumination (14 h) at 1 ± 1 °C for 28 days. Metmyoglobin formation, lipid oxidation (TBARS), instrumental colour (CIE a*) and sensory colour, discoloration, off-odour and oregano smell were determined. Active packaging significantly (P < 0.05) enhanced oxidative stability of beef steaks, depending on the oregano concentration of the active film. The display life of beef samples demonstrated that at least 1% oregano was needed for obtaining a significant increase of display life from 14 to 23 days. A concentration of 4% gave rise to unacceptable oregano smell. As a consequence, most suitable oregano extract concentrations for optimum active packaging in this system should be within the range 1-2%.     

From by-product to functional ingredient: Incorporation of avocado peel extract as an antioxidant and antibacterial agent

The work studied the possibility of avocado peel extracts replacing synthetic preservatives in mayonnaise. The extracts exhibited an IC₅₀ (concentration of extract that inhibits 50% of DPPH) value of 38.23 ± 2.33 μgextract∙mL⁻¹ and were able to inhibit more the growth of Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis), compared to ascorbic acid, proving its potential to be used as a preservative. Five mayonnaises were produced (1 negative control, 2 positive controls –with 0.02% of BHT (butylated hydroxytoluene) and 0.06% of ascorbic acid, and 2 samples –with 0.5% and 1.0% of extract), and stored at 4 °C. All mayonnaises exhibited no microbial growth and inhibited the growth of Escherichia coli and Staphylococcus aureus, proving their potential to replace synthetic preservatives. Oxidative stability revealed that the samples with extract displayed analogous results to those with synthetic antioxidants, proving the possibility of the extract replacing them. The results displayed the possibility to incorporate avocado peel extracts in mayonnaises, without compromising their stability, and their potential to replace commonly used preservatives while creating value-added foods.Industrial relevanceAvocado peels are a major by-product of avocado processing, contributing significantly to the waste generated every year. Nevertheless, it can be used to obtain extracts rich in phenolic compounds with a wide array of biological properties, that can be incorporated into different matrixes for various industries, such as food, cosmetics, and pharmaceutical. Furthermore, avocado peels are an easy-to-obtain by-product, with industrial relevance, since it allows contact between local farmers and restaurants with big industries in order to reduce the impact of this by-product while creating a value chain. Therefore, this article focuses on the incorporation of avocado peel extract into mayonnaise and its outcomes on the physical and chemical stability of the food.     

Comparative studies on the characterization and antioxidant properties of biodegradable alginate films containing ginseng extract

The physical and antioxidant properties of alginate biodegradable film incorporating white, red and extruded white ginseng extracts were investigated. No differences in moisture contents of all alginate film samples were noticeable (p > 0.05) except those film samples incorporated without ginseng extract, which had the highest moisture content. The addition of ginseng extract to alginate film decreased tensile strength and elastic modulus (p < 0.05) but increased the percent elongation at break. The presence of extracts did not significantly affect the water vapor permeability of the film samples. Alginate film containing extruded white ginseng extract at a barrel temperature of 130 °C presented the highest (61.12%) free-radical scavenging activity against the 2,2-diphenyl-1-picryhydrazyl radical (DPPH) in methanol, followed by film containing white ginseng extruded at a barrel temperature of 115 °C. Following these samples in terms of free-radical scavenging activity were film samples containing red and white ginseng extracts, respectively. These results revealed that extruded white ginseng extract has good potential to be incorporated into alginate to make antioxidant biodegradable film or coating for various food applications.