Víctor Manuel Beato

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. The fermentation and packing steps negatively affected the levels of all compounds except for SAC. The content of this compound increased during storage at room temperature whereas γ-glutamyl peptides and ACSOs were degraded to various extents. The pasteurization treatment itself had no significant effect on the concentrations of organosulfur compounds. Use of the corresponding fermentation brine in the case of the fermented product in conjunction with refrigerated storage was found to be the best method to preserve the levels of organosulfur compounds in pickled garlic stored for up to one year.

Effect of genetic characteristics and environmental factors on organosulfur compounds in garlic ( Allium sativum L.) grown in Andalusia, Spain.

The content of organosulfur compounds was determined in selected garlic cultivars grown at four locations in Andalusia, Spain. The organosulfur compounds studied were three γ-glutamyl peptides, namely, γ-l-glutamyl-S-(2-propenyl)-l-cysteine (GSAC), γ-l-glutamyl-S-(trans-1-propenyl)-l-cysteine (GSPC), and γ-l-glutamyl-S-methyl-l-cysteine (GSMC), and four cysteine sulfoxides (alliin, isoalliin, methiin, and cycloalliin). There was a significant effect of the location, cultivar, and garlic ecotype on individual organosulfur compound contents. Purple-type cultivars showed on average the highest contents of GSMC, GSAC, alliin, and methiin but the lowest isoalliin content. The impact of genotype was relatively high for GSAC, whereas this factor hardly contributed to the total variability in alliin and isoalliin content. Planting date had a significant effect on the content of alliin and isoalliin. Discriminant analysis evidenced the ability of organosulfur compounds to distinguish among garlic bulbs from different locations or ecotypes with 81 or 86% accuracy, respectively.

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. Ascorbic acid was partially or totally degraded during storage, the degradation rate depending on the storage conditions and the vegetable matrix. Benzene levels higher than 10 μg/L were found in cucumbers and caperberries containing both additives, but only when packed in plastic pouches and after prolonged storage at room temperature. In these conditions, an appreciable browning of brine, related to AA degradation, was also found. The use of benzoate alone had a significant influence on vegetable color, but flavor was not significantly affected at the benzoate levels tested. On the basis of the present study, benzoates should be removed from fermented vegetable formulations containing ascorbic acid to eliminate possible benzene formation during long-term storage.

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. Studies with a model solution of AA and sarcosine heated at 121°C for 30 min suggested that the main mechanism for the inhibitory effect of sarcosine on AA formation was the Michael reaction. Graphical Abstract

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. A varying number of compounds from each chemical family underwent significant changes because of the post-fermentation and packing stages. Among them, some typical reaction products of lipid oxidation (e.g. (E)-2-decenal and (E,E)-2,4-decadienal) increased with the post-fermentation in Manzanilla cultivar, and also as a result of packing in all three cultivars.

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. The MSG content also remained stable in pasteurised green table olives. On the contrary, MSG was extensively degraded (>75% degradation) after 54 weeks of storage in unpasteurised green olives with a higher degradation rate in glass bottles compared with plastic pouches. In the presence of potassium sorbate, MSG was also considerably degraded in olives packed in plastic pouches (>50% degradation), but hardly degraded in glass bottles. The results indicate that MSG degradation in olives is due to the action of both lactic acid bacteria and yeasts, with the formation of γ-aminobutyric acid as the major end-product.

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. RESULTS In PET + MDPE/EVOH (polyethylene terephthalate + medium-density polyethylene/ethylene vinyl alcohol) pouches, pasteurization provoked severe browning which drastically decreased their color shelf life (<6 weeks). However, this browning did not occur in the unpasteurized product without preservatives owing to the presence of microorganisms. In AlOx-coated PET + MDPE (aluminum oxide coating on polyethylene terephthalate + medium-density polyethylene) pouches, color changes were small or negligible throughout storage, especially if ascorbic acid was added to the packing solution (shelf life > 6.5 months). CONCLUSION The plastic material had a significant effect on the retention of color of the pasteurized product. The use of AlOx-coated PET + MDPE pouches could be an alternative to traditional packaging for the pasteurization and storage of Spanish-style green olives from a color quality standpoint.