Papadopoulou Olga S, Argyri Anthoula A, Bikouli Vasiliki C, Lambrinea Eleni, Chorianopoulos Nikos
Institute of Technology of Agricultural Products, Hellenic Agricultural Organization-DIMITRA, 14123 Lycovrissi, Attica, Greece.
Foods. 2022 Sep 15;11(18):2855. doi: 10.3390/foods11182855.
The aim of the current study was to assess the efficacy of Na-alginate edible films as vehicles for delivering lactic acid bacteria (LAB) with functional properties to sliced cheeses, with or without high-pressure processing (HPP). A three-strain LAB cocktail (Lactococcus lactis Τ4, Leuconostoc mesenteroides Τ25 and Lacticaseibacillus paracasei Τ26) was incorporated into Na-alginate solution in a final population of 9 log CFU/mL. The cheese slices (without or with HPP treatment at 500 MPa for 2 min) were packaged in contact with the LAB edible films (LEFs), and subsequently vacuum packed and stored at 4 °C. Cheese slices without the addition of films, with or without HPP treatment, were used as controls. In all cases, microbiological, pH and sensory analyses were performed, while the presence and the relative abundance of each strain during storage was evaluated using Random Amplified Polymorphic DNA-PCR (RAPD-PCR). In addition, organic acid determination and peptide analysis were performed using high-performance liquid chromatography. The results showed that in cheeses without HPP treatment, the microbiota consisted mostly of mesophilic LAB and lactococci (>7.0 log CFU/g), while HPP caused a reduction in the indigenous microbiota population of approximately 1−1.5 log CFU/g. In the LEF samples, the populations of mesophilic LAB and lactococci were maintained at levels of >6.35 log CFU/g during storage, regardless of the HPP treatment. Sensory evaluation revealed that the LEF samples without HPP had a slightly more acidic taste compared to the control, whereas the HPP-LEF samples exhibited the best organoleptic characteristics. RAPD-PCR confirmed that the recovered strains were attributed to the three strains that had been entrapped in the films, while the strain distribution during storage was random. Overall, the results of the study are promising since the functional LAB strains were successfully delivered to the products by the edible films until the end of storage.
本研究的目的是评估海藻酸钠可食性薄膜作为载体，在有无高压处理（HPP）的情况下，将具有功能特性的乳酸菌（LAB）递送至切片奶酪中的效果。将三种乳酸菌混合菌液（乳酸乳球菌T4、肠系膜明串珠菌T25和副干酪乳杆菌T26）以最终浓度9 log CFU/mL加入到海藻酸钠溶液中。将奶酪切片（未进行HPP处理或在500 MPa下进行2分钟的HPP处理）与含乳酸菌的可食性薄膜（LEF）接触包装，随后进行真空包装并在4℃下储存。未添加薄膜的奶酪切片，无论有无HPP处理，均用作对照。在所有情况下，均进行微生物学、pH值和感官分析，同时使用随机扩增多态性DNA-PCR（RAPD-PCR）评估储存期间各菌株的存在情况和相对丰度。此外，使用高效液相色谱法进行有机酸测定和肽分析。结果表明，在未进行HPP处理的奶酪中，微生物群主要由嗜温乳酸菌和乳球菌组成（>7.0 log CFU/g），而HPP使本地微生物群数量减少了约1-1.5 log CFU/g。在LEF样品中，无论是否进行HPP处理，嗜温乳酸菌和乳球菌的数量在储存期间均保持在>6.35 log CFU/g的水平。感官评价显示，未进行HPP处理的LEF样品与对照相比，酸味略重，而经HPP处理的LEF样品表现出最佳的感官特性。RAPD-PCR证实，回收的菌株属于包裹在薄膜中的三种菌株，且储存期间菌株分布是随机的。总体而言，该研究结果很有前景，因为功能性LAB菌株通过可食性薄膜成功递送至产品中直至储存结束。
