Tecnológico Nacional de México-Instituto Tecnológico de Ciudad Madero, Centro de Investigación en Petroquímica, Prolongación Bahía de Aldair, Parque de la Pequeña y Mediana Industria, Altamira, Mexico.
Instituto de Ingeniería, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico.
J Appl Microbiol. 2021 Sep;131(3):1162-1176. doi: 10.1111/jam.15025. Epub 2021 Mar 18.
Analysing the antimicrobial activity-against food-borne micro-organisms-of modified chitosan-starch films using formic and acetic acid as chitosan solvents and Melicoccus bijugatus leaves and fruit extracts.
The films' antimicrobial activity against mesophilic aerobic bacteria, total coliform and fungi were also analysed, in accordance with the Mexican Official Norms (NOM-092-SSA1-1994, NOM-111-SSA1-1994 and NOM-113-SSA1-1994). The pH values of the films and extracts were measured, and the volatile compounds of the extracts and two films were determined by Gas Chromatography-Mass Spectrometry (GC-MS) considering the relationship among the type of compounds, extracts concentration, films' pH and the antimicrobial activity against bacteria and fungi. The best results are obtained by films with formic acid and 10% (v/v) of leaf and fruit extracts, in comparison with untreated chitosan-starch films.
The extracts' compounds improved the films' antimicrobial capacity and inhibited the growth of micro-organisms with no previous sterilization required. It is correlated to the pH of the media, the combination of solvent/extract used and its concentration.
This is one of the few researches where the antimicrobial activity of M. bijugatus extracts is studied. It was found that the presence of these extracts is capable of improving the antimicrobial activities of chitosan-starch films. The performance of the modified films suggests their potential application as novel food packaging materials and encourages further research.
分析甲酸和乙酸作为壳聚糖溶剂以及桃金娘叶和果实提取物对改性壳聚糖-淀粉膜的抗食源微生物抗菌活性。
根据墨西哥官方标准（NOM-092-SSA1-1994、NOM-111-SSA1-1994 和 NOM-113-SSA1-1994），还分析了这些膜对需氧嗜温菌、总大肠菌群和真菌的抗菌活性。测量了膜和提取物的 pH 值，并通过气相色谱-质谱联用（GC-MS）确定了提取物和两种膜的挥发性化合物，同时考虑了化合物类型、提取物浓度、膜 pH 值与细菌和真菌抗菌活性之间的关系。与未经处理的壳聚糖-淀粉膜相比，用甲酸和 10%（v/v）叶和果实提取物制成的膜获得了最佳结果。
提取物中的化合物提高了膜的抗菌能力，并在无需事先灭菌的情况下抑制了微生物的生长。这与介质的 pH 值、所用溶剂/提取物的组合及其浓度有关。
这是少数研究桃金娘提取物抗菌活性的研究之一。研究发现，这些提取物的存在能够提高壳聚糖-淀粉膜的抗菌活性。改性膜的性能表明它们有作为新型食品包装材料的应用潜力，并鼓励进一步研究。
