Microbial and Chemical Characterization of Natural-Style Green Table Olives from the Gordal, Hojiblanca and Manzanilla Cultivars.

Microbial and biochemical changes in the brine during the spontaneous fermentation of Gordal, Hojiblanca and Manzanilla olive cultivars processed according to the natural style were monitored. The microbial composition was assessed through a metagenomic study. Sugars, ethanol, glycerol, organic acids and phenolic compounds were quantified by standard methods.

Microbial community and volatilome changes in brines along the spontaneous fermentation of Spanish-style and natural-style green table olives (Manzanilla cultivar).

Microbial community and volatilome of brines were monitored during the spontaneous fermentations of Spanish-style and Natural-style green table olives from Manzanilla cultivar. Fermentation of olives in the Spanish style was carried out by lactic acid bacteria (LAB) and yeasts, whereas halophilic Gram-negative bacteria and archaea, along with yeasts, drove the fermentation in the Natural style. Clear differences between the two olive fermentations regarding physicochemical and biochemical features were found.

Production of volatile compounds by wild-type yeasts in a natural olive-derived culture medium.

The production of volatile compounds in naturally fermented green table olives from Manzanilla cultivar was investigated. A total of 62 volatile compounds were detected after 24 weeks of fermentation. To clarify the contribution of yeasts to the formation of these compounds, such microorganisms were isolated from the corresponding fermenting brines.

Aroma profile and volatile composition of black ripe olives (Manzanilla and Hojiblanca cultivars).

The aroma profile and volatile composition of 8 samples of black ripe olives from Manzanilla and Hojiblanca cultivars were analyzed with the aim to characterize this type of table olive. The aroma of samples was described by a sensory panel using quantitative descriptive analysis (QDA), whereas the volatiles were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). Eleven odor descriptors (briny, sautéed mushroom, earthy/soil-like, oak barrel, nutty, artificial fruity/floral, natural fruity/floral, vinegary, alcohol, fishy/ocean-like, and cheesy) were evaluated, of which only one descriptor (briny) showed a significant difference between cultivars.

Changes in volatile composition during the processing and storage of black ripe olives.

The present study revealed the effects of each step of black ripe olive processing (preservation, darkening, packing + sterilization) and storage on the volatile composition of two olive cultivars (Manzanilla and Hojiblanca). The preservation step enriched the volatile profile of the olives, mainly in ethyl acetate, methyl acetate, and ethanol. The darkening step produced the total or partial elimination of 55-65% of the volatiles identified before this step.

Microbiota and Metabolite Profiling of Spoiled Spanish-Style Green Table Olives.

The aim of the present study was to assess the malodorous spoilages of Spanish-style green table olives through microbial and metabolite composition using current measuring techniques (e.g., high-throughput DNA sequencing, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry).

Effect of Spanish-style processing steps and inoculation with Lactobacillus pentosus starter culture on the volatile composition of cv. Manzanilla green olives.

The effects of the main steps of Spanish-style processing (alkaline treatment and fermentation) on the volatile composition of cv. Manzanilla green olives were studied. Both spontaneous and controlled fermentations were considered.

Effect of post-fermentation and packing stages on the volatile composition of Spanish-style green table olives.

The volatile profile of Spanish-style green table olives after fermentation and the changes in volatile compounds that occurred as a result of the post-fermentation and subsequent packing stage were explored by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS). Three olive cultivars (Manzanilla, Gordal, and Hojiblanca) were processed and olive samples were taken at three different times throughout the elaboration: after fermentation, after post-fermentation, and after packing. A total of 132 volatile compounds were identified, including 10 phenols, 25 alcohols, 11 acids, 39 esters, 8 hydrocarbons, 14 carbonyl compounds, 17 terpenes, and 6 other compounds.

Stability of color in Spanish-style green table olives pasteurized and stored in plastic containers.

Background: There is an increasing interest in the use of pasteurizable plastic packaging by the olive industry. In order to investigate the change from traditional glass or varnished can containers to plastic packaging, the proper plastic material that is compatible with fermented olives while maintaining color quality during pasteurization treatment and storage must be selected. This work is focused on color stability in two distinct pasteurizable plastic containers with different oxygen permeability.

Assays to control the development of the green staining alteration in Spanish-style green olives of the Gordal variety.

Background: Olives of the Gordal variety processed according to the Spanish style sometimes develop an alteration in color known as green staining (GS), due to the formation of harmless copper-chlorophyll complexes, which makes the product less valuable. The aim of this study was to investigate methods to minimize the impact that this alteration has for the table olive industry.

Results: Calcium chloride, sorbic, benzoic and ascorbic acids and SO2 did not inhibit the development of the alteration in olives packed under their own fermentation brine or new fresh brine.

Stability of monosodium glutamate in green table olives and pickled cucumbers as a function of packing conditions and storage time.

The effects of different packing conditions and storage times on the stability of monosodium glutamate (MSG) added to two different fermented vegetables (Spanish-type green table olives and pickled cucumbers) were studied. Factors such as packaging material (glass bottle versus plastic pouch), heat treatment (pasteurisation versus non-pasteurisation), and the presence or not of a preservative compound (potassium sorbate) were considered. The MSG content of pickled cucumbers was stable for up to 1 year of storage in all packing conditions studied.

Comparative study of the use of sarcosine, proline and glycine as acrylamide inhibitors in ripe olive processing.

The main purpose of this study was to evaluate the inhibitory effect on acrylamide (AA) formation and the impact on sensory characteristics in ripe olives of three selected amino acids (sarcosine, proline and glycine), which previously showed high AA inhibition rates in an olive model system. Each amino acid was separately added to packing solutions to give 100 or 200 mM at equilibrium, prior to a sterilisation treatment at 121°C. The results showed that sarcosine at 100 mM may be a good candidate for reducing the AA content in ripe olives with a limited effect on sensory characteristics.

Degradation of ascorbic acid and potassium sorbate by different Lactobacillus species isolated from packed green olives.

The aim of this research was to ascertain the lactic acid bacteria responsible for the degradation of ascorbic acid and/or potassium sorbate, isolated from packed green olives where these additives had diminished. A total of 14 isolates were recovered from samples of different green olive containers. According to partial sequencing of the 16S rRNA coding gene, Lactobacillus parafarraginis, Lactobacillus rapi, Lactobacillus pentosus, Lactobacillus paracollinoides, and Pediococcus ethanolidurans were identified.

Effect of processing and storage time on the contents of organosulfur compounds in pickled blanched garlic.

The influence of processing, with and without fermentation, on the contents of organosulfur compounds, namely, γ-glutamyl peptides, S-alk(en)yl-L-cysteine sulfoxides (ACSOs), and S-allyl-L-cysteine (SAC), in pickled blanched garlic was evaluated. For each processing type, the effect of the preservation method and storage time was also analyzed. Blanching in hot water (90 °C for 5 min) hardly affected the individual organosulfur compound content.

Fermented vegetables containing benzoic and ascorbic acids as additives: benzene formation during storage and impact of additives on quality parameters.

Chemical and sensorial changes related to the use of benzoates and ascorbic acid as additives in packed fermented vegetables were investigated. For this, three selected vegetables (green olives, cucumbers, and caperberries) stored under different conditions (glass or plastic containers, ambient or refrigerated storage) were used. In all cases, benzoic acid remained unchanged (glass bottle) or decreased slightly (plastic pouch) at prolonged storage.

D-amino acid formation in sterilized alkali-treated olives.

The occurrence of d-amino acids in commercial ripe olives, a well-known sterilized alkali-treated product, was investigated by high-performance liquid chromatography (HPLC) with precolumn automatic derivatization. Absolute amounts of D-amino acids were in total 18.6-38.

Vitamin content and amino acid composition of pickled garlic processed with and without fermentation.

The effect of processing, with and without fermentation, upon the nutritional composition of pickled garlic was evaluated. On a dry basis, the fermented product had a higher content of riboflavin, alpha-tocopherol, and most individual amino acids but a lower thiamin level than the unfermented product. Ascorbic acid was totally lost during processing.