Spanish-style Green Olives Research Articles

Content of Biogenic Amines in Table Olives

Content of biogenic amines in flesh and brines of table olives was determined by high-pressure liquid chromatography analysis of their benzoyl derivatives. No biogenic amines were found in the flesh of fresh fruits at any stage of ripeness. Contents of biogenic amines in Spanish-style green or stored olives increased throughout the brining period but were always higher in the former. Putrescine was the amine found in the highest concentration. Small quantities of cadaverine were found in the samples taken after 3 months of brining. This compound and histamine, tyramine, and tryptamine were also found in samples taken after 12 months. Gordal cultivar showed the highest contents, followed by Manzanilla and Hojiblanca. No relationship was found between contents of biogenic amines and lactic acid production or table olive spoilages, although zapatera olives had considerably higher amounts than those brines that had undergone a normal process. Concentrations in directly brined olives were markedly lower than contents in Spanish-style olives. With respect to partition between flesh and brine, there was equilibrium between both media in the case of Spanish-style olives, whereas the contents in directly brined olives were higher in flesh than brine.

Bacterias del ácido láctico en la fermentación de aceitunas de mesa

The paper reviews the characteristics for the lactic acid bacteria (LAB) growth in the three main table olive types in the international trade. The only typical spontaneous lactic process is that followed in the Spanish-style green olives. The growth of LAB throughout storage in brine of ripe olives and fermentation of naturally ripe (black) olives depends on various factors such as olive cultivars, sodium chloride concentration, initial pH correction, etc. The knowledge of the spontaneous growth conditions is essential for a better microbiological control and the efficient use of starter cultures in these fermentations.

Effect of Preservation Treatment, Light, and Storage Time on Quality Parameters of Spanish-Style Green Olives

The influence of acidity−salt level, pasteurization, light, and storage time on pH, titratable acidity, brine color, and firmness and color of the fruit was determined in packed green olives (whole, pitted, and stuffed with pepper paste). There was a significant increase in pH during storage, indicating microbiological instability, in the case of the nonpasteurized pitted olives with the lowest acidity−salt level (0.3−3.0%). In general, the pasteurized samples were less firm and had lower color index [i = (4R635 + R590 − 2R560)/3] and a darker brine (as measured by the parameter A440 − A700) than the nonpasteurized samples. The color index was highly correlated with the parameter L*. The samples stored in the presence of light had a paler brine, but higher values of i, than those stored in darkness. During storage the firmness degraded slowly, with the data fitting first-order kinetics well (r > 0.90). The color of the olives also degraded with time, mainly in the pasteurized samples stored in darkness. The repercussions on the product's shelf life are discussed. Keywords: Olives; storage; shelf life; firmness; color

4-Hydroxycyclohexanecarboxylic Acid as a Substrate for Cyclohexanecarboxylic Acid Production during the “Zapatera” Spoilage of Spanish-Style Green Table Olives

Zapatera spoilage was reproduced in Spanish-style green olive brines adjusted to pH 5 and with a concentration of 5% (wt/vol) NaCl. A relationship between the formation of the compound responsible for the zapatera off odor, cyclohexanecarboxylic acid, and consumption of a new compound isolated from olive brines, 4-hydroxycyclohexanecarboxylic acid, was established. When the latter compound was added to a synthetic medium inoculated with a concentrated microbial suspension from a zapatera brine, cyclohexanecarboxylic acid was formed. 4-Hydroxy-cyclohexanecarboxylic acid was not detected in fresh olives, NaOH solutions, or water washes. In normal fermentation brines it was not detected after 30 days of brining, its concentration increasing in a progressive manner thereafter during typical lactic acid fermentation of Spanish-style green olives.

Biochemical Changes in Phenolic Compounds during Spanish-Style Green Olive Processing

Phenolic compounds have been determined by HPLC in the flesh of olives and brines of two cultivars (Manzanilla and Hojiblanca) during Spanish-style green olive processing. The NaOH treatment hydrolyzed oleuropein into hydroxytyrosol (3,4-dihydroxyphenylethanol) and elenolic acid glucoside. After a rapid diffusion of hydroxytyrosol from the flesh of fruits into the brines, the concentration of the o-diphenol remained practically constant throughout the lactic acid fermentation step. In contrast, elenolic acid glucoside increased in concentration in the olive brines during the first few days of brining but disappeared after 100-200 days. Other minor phenolic compounds also diffused rapidly into the olive brines during the first few days of brining. Caffeic acid, oleuropein, and p-coumaric acid diminished in concentration throughout the fermentation period, whereas the concentration of tyrosol (4-hydroxyphenylethanol) remained constant.

Use of Lactobacillus plantarum LPCO10, a Bacteriocin Producer, as a Starter Culture in Spanish-Style Green Olive Fermentations

Bacteriocin-producing Lactobacillus plantarum LPCO10 and its non-bacteriocin-producing, bacteriocinimmune derivative, L. plantarum 55-1, were evaluated separately for growth and persistence in natural Spanish-style green olive fermentations. Both strains were genetically marked and selectively enumerated using antibiotic-containing media. Plasmid profile and bacteriocin production (bac) were used as additional markers. When olive brines were inoculated at 10 CFU/ml, the parent strain, LPCO10, proliferated to dominate the epiphytic microflora, sharing high population levels with other spontaneously occurring lactobacilli and persisting throughout the fermentation (12 weeks). In contrast, the derivative strain could not be isolated after 7 weeks. Stability of both plasmid profile and bac (LPCO10 strain) or bac (55-1 strain) phenotype was shown by L. plantarum LPCO10 and L. plantarum 55-1 isolated throughout the fermentation. Bacteriocin activity could be found in the L. plantarum LPCO10-inoculated brines only after ammonium sulfate precipitation and concentration (20 times) of the final brine. Spontaneously occurring lactobacilli and lactic coccus populations, which were isolated from each of the fermenting brines studied during this investigation, were shown to be sensitive to the bacteriocins produced by L. plantarum LPCO10 when tested by the drop diffusion test. The declines in both pH and glucose levels throughout the fermentative process were similar in L. plantarum LPCO10- and in L. plantarum 55-1-inoculated brines and were comparable to the declines in the uninoculated brines. However, the final concentration of lactic acid in L. plantarum LPCO10-inoculated brines was higher than in the L. plantarum 55-1-inoculated brines and uninoculated brines. These results indicated that L. plantarum LPCO10 may be useful as a starter culture to control the lactic acid fermentation of Spanish-style green olives.