槟榔炮制阶段优势霉菌分析及其防霉剂的研制

分别采用营养琼脂培养基、高盐察氏培养基、牛肉膏蛋白胨培养基、高氏1号培养基、马铃薯营养琼脂培养基（加入山梨醇）分析炮制阶段槟榔中微生物菌群的基本构相,其中霉菌为主要菌群,数量为总菌落数的30％左右;进一步对炮制阶段槟榔中的霉菌进行分离纯化,经斜面和湿室栽片培养后,所得青霉菌株数为菌株总数的40％左右,表明青霉为优势霉菌。分别采用钠他霉素、脱氢醋酸钠及其复合防霉剂对青霉进行抑菌活性测定,三者的MIC值分别为10,90,80mg／kg,抑菌圈直径分别为8．4,9．8,9．1nim,同时确定钠他霉素与脱氢醋酸钠以1：500混合时对青霉的防霉效果最佳。     

纳他霉素的特性及应用

介绍了链霉菌产生的多烯大环内酯类抗真菌剂纳他霉素的特性及其应用。在特性方面简述了其理化性质、抗微生物性质、作用机制和安全性；在应用方面详述了纳他霉素在乳酷防霉中的应用并概要介绍了它在饮料、食品、饲料及医药方面的应用。     

天然防腐剂——那他霉素

The article mainly introduced the character of antimicrobial Natamycin, the preservative mechanism, the application in meat products was reviewed and the development of Natamycin was proposed.     

Effect of calcium and/or barium crosslinking on the physical and antimicrobial properties of natamycin-loaded alginate films

The preparation of alginate films with suitable properties requires a two-step contact with reticulating agents: initially a weakly structured pre-film is formatted which is further crosslinked in a second stage by immersion in a more concentrated solution. The present work evaluated the effects of a combined crosslinking procedure using calcium and barium ions on the physical and morphological properties of alginate-based films containing natamycin as antimicrobial agent. The release behavior of natamycin in water was evaluated as well as the antimicrobial activity against four target microorganisms, which are common cheese product contaminants. Films attributes were affected by the type of ion used in the second stage while the natamycin release rate and the antimicrobial activity were influenced by the ion used in the first stage. Films crosslinked with Ba²⁺ in the first and Ca²⁺ in the second stage (Ba–Ca films) exhibited physical properties very similar to films crosslinked with calcium in both stages. Release kinetics of natamycin in water fitted well to Fick's second law diffusional model, with effective diffusivity values ranging from 0.40 × 10⁻¹¹ to 1.74 × 10⁻¹¹ cm²/s. Ba–Ca films presented the lowest natamycin diffusion coefficient and the smallest inhibition zone diameter against the four microorganisms tested.     

Evaluation of a chitosan-based edible film as carrier of natamycin to improve the storability of Saloio cheese

The purpose of this study was to evaluate the effects of the application of chitosan coating containing natamycin on the physicochemical and microbial properties of semi-hard cheese. Three cheese groups were prepared: samples without coating, samples coated with chitosan and with chitosan containing 0.50 mg mL⁻¹ of natamycin, whose minimum inhibitory concentration was previously determinated on cheese surface. Microbiological analyses showed that natamycin coated samples presented a decrease on moulds/yeasts of 1.1 log (CFU g⁻¹) compared to control after 27 days of storage. Addition of natamycin also affected O₂ and CO₂ permeability, increasing from 7.12 to 7.68 × 10⁻¹⁵ g·(Pa s m)⁻¹, and from 10.69 to 64.58 × 10⁻¹⁴ g·(Pa s m)⁻¹, respectively. The diffusion coefficient values of natamycin from the film to phosphate buffered saline solution and to the cheese were 3.60 × 10⁻¹⁰ and 1.29 × 10⁻¹² cm² s⁻¹, respectively. This study demonstrated that chitosan-based coating/films can be used as release system containing natamycin to create an additional hurdle for moulds/yeasts in cheese thus contributing to extend its shelf-life.     

多烯类抗菌剂纳他霉素

对纳他霉素的抑菌机理、安全性进行介绍,综述了其应用现状,并对其应用前景进行展望,以期为纳他霉素的进一步研究和应用提供参考。     

Scope extension validation of a LC-MS method for the inspection of preservatives in butter

Butters are considered as “natural products” by many consumers, once they are obtained from milkfat without adding of any additive, except sodium chloride, starter cultures and natural dyes. The main goals of this study were to extend the scope of a previously developed method, including a new analyte (benzoic acid) and new matrices (butter and margarine), and thus evaluate the content of preservatives in national and imported butters traded in Brazil. Samples (n = 51) from inspected establishments in Argentina (n = 2), Brazil (n = 40), France (n = 7) and Uruguay (n = 2) were assessed by liquid chromatography-tandem mass spectrometry. Two screening inspection rounds were carried out between November, 2015 and January, 2016. Non-compliance rates were 36.4% in 2015 and 22.2% in 2016 for Brazilian butters. It was shown that preservatives are irregularly added to butters by many factories, contrary to regulation, and without proper declaration on labeling. The limits of quantitation (LOQ) were set to 25.00 mg kg⁻¹ (benzoic acid), 1.25 mg kg⁻¹ (natamycin), 3.13 mg kg⁻¹ (nisin) and 2.50 mg kg⁻¹ (sorbic acid). Except nisin, any of the researched preservatives was detected in a total of 12 samples, in concentrations that ranged from <LOQ–235.67 mg kg⁻¹ (benzoic acid), 8.26–35.60 mg kg⁻¹ (natamycin) and 4.52–1007.17 mg kg⁻¹ (sorbic acid). The method was also checked on margarine samples, revealing concentrations that ranged from 43.72 to 359.17 mg kg⁻¹ (benzoic acid) and from 509.00 to 1102.67 mg kg⁻¹ (sorbic acid), respectively. Our findings demonstrate that there is a need for stricter control in butter processing, with the aim to ensure food safety and to safeguard consumers.     

纳他霉素在食品工业中的最新研究现状

纳他霉素是一种高效生物防腐剂。本文介绍了纳他霉素的理化特性、抗微生物活性和作用机理;综述了纳他霉素在乳制品、肉制品、饮料、果蔬保鲜、焙烤食品、调味品及其他食品中的应用,并对其发展前景进行了展望,以期为纳他霉素的进一步研究和应用提供参考。     

超声萃取－紫外分光光度法测定酸奶中的纳他霉素

在甲醇和醋酸介质下,采用超声萃取进行前处理,建立一种紫外分光光度法快速测定酸奶中纳他霉素的方法。优化了超声萃取时间、波长、酸度等试验条件,并由正交试验进一步验证。对几种酸奶样品中纳他霉素进行测定,回收率均在92．89％～104．61％之间。     

霉克和尼萨普林在巴氏灭菌海参制品中的应用

霉克主要成分是纳他霉素（Natamicin），对霉菌和酵母菌有抑菌作用。尼萨普林（Nisaplin）是乳酸链球菌素（Nisin）与氯化钠等成分的混合制剂。乳酸链球菌素（Nisin）是一种由34个氨基酸组成的天然抗菌素，对革兰氏阳性菌具有抑菌作用。本文介绍了上述两种防腐剂在海参保藏上的应用。