Benefits of the Use of Lactic Acid Bacteria Starter in Green Cracked Cypriot Table Olives Fermentation

Abstract

Table olives are one of the most established Mediterranean vegetables, having an exponential increase consumption year by year. In the natural-style processing, olives are produced by spontaneous fermentation, without any chemical debittering. This natural fermentation process remains empirical and variable since it is strongly influenced by physicochemical parameters and microorganism presence in olive drupes. In the present work, Cypriot green cracked table olives were processed directly in brine (natural olives), using three distinct methods: spontaneous fermentation, inoculation with lactic acid bacteria at a 7% or a 10% NaCl concentration. Sensory, physicochemical, and microbiological alterations were monitored at intervals, and major differences were detected across treatments. Results indicated that the predominant microorganisms in the inoculated treatments were lactic acid bacteria, while yeasts predominated in control. As a consequence, starter culture contributed to a crucial effect on olives fermentation, leading to faster acidification and lower pH. This was attributed to a successful lactic acid fermentation, contrasting the acetic and alcoholic fermentation observed in control. Furthermore, it was established that inhibition of enterobacteria growth was achieved in a shorter period and at a significantly lower salt concentration, compared to the spontaneous fermentation. Even though no significant variances were detected in terms of the total phenolic content and antioxidant capacity, the degradation of oleuropein was achieved faster in inoculated treatments, thus, producing higher levels of hydroxytyrosol. Notably, the reduction of salt concentration, in combination with the use of starter, accented novel organoleptic characteristics in the final product, as confirmed from a sensory panel; hence, it becomes obvious that the production of Cypriot table olives at reduced NaCl levels is feasible.

Evolution of Bacterial Communities, Physicochemical Changes and Sensorial Attributes of Natural Whole and Cracked Picual Table Olives During Spontaneous and Inoculated Fermentation

“…Microbial changes were monitored at several time points (days 0, 8, 15, 22, 29, 45, 60, 90, 120), throughout the process. Brines were determined for their total viable count (TVC), LAB, Yeasts, Enterobacteriaceae, coliforms, and coagulasenegative staphylococci (CoNS) ( Table 2), as described previously (Anagnostopoulos et al, 2020). Results expressed as log cfu/ml and analyses applied in triplicates.…”

“…1 http://viceroy.eeb.uconn.edu/estimates/index.html Finally, the changes of the main phenolic compounds (oleuropein and hydroxytyrosol) determined chromatographically using HPLC (Waters 1525), as described by Anagnostopoulos et al (2020). Results were expressed as means (mg/g or mg/ml) and standard deviations of three replicates.…”

“…Color alternations were monitored using a CR200 Chroma Meter (Minolta camera Co., Ltd.), as described previously (Anagnostopoulos et al, 2020). The analysis performed in ca.…”

Characterization and Processing of Table Olives: A Special Issue

“…In the work “Benefits of the Use of Lactic Acid Bacteria Starter in Green Cracked Cypriot Table Olives Fermentation”, Anagnostopoulos et al [ 3 ] study the microbial and physicochemical changes of Cypriot green cracked table olives during spontaneous or controlled fermentation process at industrial scale. For this purpose, the authors processed Cypriot green cracked table olives directly in brine (natural olives), using three distinct methods: spontaneous fermentation, inoculation with commercial lactic acid bacteria at a 7%, or a 10% NaCl concentration.…”

“…To conclude, the present special issue consists of 10 original research papers and two review articles. The research papers, focused on recent research advances related to characterization and processing of table olives, have covered microbiological and chemical changes in table olives during spontaneous or controlled fermentation employing different cultivars [ 3 ], characterization of their composition of volatiles and the sensory profile [ 5 , 6 , 7 ], mineral composition [ 8 ] and bioavailability [ 9 ], changes in bioactive components (chlorophylls) by processing [ 10 ], optimized use of starter cultures for the improvement of the different fermentative processes [ 4 , 5 ], and new strategies to reduce sodium and additives, to stabilize the organoleptic properties and avoid defects [ 11 , 12 ].…”