Laboratory of Food Chemistry and Technology, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Division of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece.
Food Res Int. 2024 Sep;191:114710. doi: 10.1016/j.foodres.2024.114710. Epub 2024 Jun 28.
Table olives are among the most popular fermented foods and cv. Chalkidiki green table olives are particularly popular in both Greek and international markets. This work aimed at comparatively investigating the effect of processing method on the production of Spanish-style and natural cv. Chalkidiki green olives during fermentation and 12-month storage in brines with different chloride salts composition (NaCl, KCl, CaCl) at industrial scale. All delivered products were safe with satisfactory color and texture characteristics. Employment of UPLC-HRMS revealed differences in metabolites' profile of polar extracts from olives and brines between the processing methods. Τhe application of alkali treatment drastically decreased the content of hydroxytyrosol and tyrosol in drupes, still an essential amount (1037-2012 and 385-885 mg/kg dry flesh, respectively) of these health-promoting phenolic compounds was retained in all products, even after storage. Noteworthy, fermentation of natural olives in brine (5 % NaCl) yielded in products with significantly lower Na levels in olive flesh (1.7 g/100 g), followed by Spanish-style olives fermented in low (4 %) and high (8 %) NaCl brines (2.7 and 5.2 g Na/100 g, respectively), supporting the efforts toward the establishment of table olives as functional food. Moreover, maslinic and oleanolic acids content was 1.5-2-fold higher in the natural table olives compared to the Spanish-style ones owing to the detrimental effect of alkali treatments. The processing method did not exert a differential effect on α-tocopherol content of olives. Sensory analysis indicated that all the final products were acceptable by consumers, with a slight preference for Spanish-style green olives fermented in brines with 50 % lower NaCl content. Present findings could be beneficial to the ongoing endeavor directed for the establishment of table olives as a source of bioactive compounds that concerns both industrial and scientific communities.
油橄榄是最受欢迎的发酵食品之一，而 Chalkidiki 绿橄榄在希腊和国际市场上尤其受欢迎。本工作旨在比较研究加工方法对西班牙式和天然 Chalkidiki 绿橄榄在发酵过程中的影响，并在工业规模下，在不同氯化物盐组成（NaCl、KCl、CaCl）的盐水中进行 12 个月的储存。所有产品均安全，色泽和质地令人满意。超高效液相色谱-高分辨率质谱联用分析（UPLC-HRMS）表明，不同加工方法的橄榄和盐水极性提取物的代谢物谱存在差异。碱处理的应用大大降低了核果中羟基酪醇和酪醇的含量，但这些促进健康的酚类化合物在所有产品中仍保留了一定的含量（分别为 1037-2012 和 385-885mg/kg 干果肉），甚至在储存后也是如此。值得注意的是，在 5%NaCl 盐水中发酵的天然橄榄产生的橄榄肉中 Na 含量显著降低（1.7g/100g），其次是在低（4%）和高（8%）NaCl 盐水中发酵的西班牙式橄榄（分别为 2.7 和 5.2g Na/100g），这支持了将橄榄作为功能性食品的努力。此外，由于碱处理的不利影响，天然橄榄中的齐墩果酸和熊果酸含量是西班牙式橄榄的 1.5-2 倍。加工方法对橄榄中α-生育酚的含量没有产生差异影响。感官分析表明，所有最终产品均受到消费者的欢迎，对用 50%低 NaCl 含量的盐水发酵的西班牙式绿橄榄稍有偏好。本研究结果可能有益于正在进行的将橄榄作为生物活性化合物来源的努力，这既关系到工业界，也关系到科学界。
