Changes in physicochemical characteristics, substrate depletion, and product formation during fermentation were followed in both brine and olive juice in order to achieve a complete knowledge of fermentation chemistry in Spanish-type green olives. Both spontaneous and controlled fermentations were investigated. Fermentation rate, irrespective of the type of fermentation, was lower in olive juice than in brine, but the main acid products eventually reached equilibrium. Final free acidity remained significantly (p < 0.05) higher, and combined acidity remained lower, in brine than in olive juice in both fermentations, but differences in final pH were not significant in controlled fermentation. Final concentrations of lactic and formic acids were significantly (p < 0. 05) higher, and those of ethanol and succinic acid were lower, in controlled fermentation than in spontaneous fermentation. Butanediol, attributable to Enterobacteriaceae growth, was formed only in the latter case. Calculated carbon recoveries were not significantly (p < 0.05) different in any case, giving a mean of some 78%.

Three processes for preparing peeled pickled garlic were studied: (P) packing directly with an acidified brine, followed by pasteurization (90°C, 8 min); (B) blanching with hot water (90°C, 15 min) before packing, followed by a preservation treatment (pasteurization, preservatives + refrigeration); and (MB) same as B, except that microwave blanching was used (120g garlic cloves, 825W, 1.5 min). All products were microbiologically stable but fructans were hydrolyzed during storage at 27°C. A green pigment was also apparent in (P). Products from (B) or (MB) had better quality than that from (P). Most stable and best quality products resulted from the blanching treatments and water blanching resulted in the product with best color.addition of the starter, and to inactivate softening enzymes (Fleming et al., 1983). Blanching with boiling water for 15 min has been used for deactivating alliinase before determination of alliin in garlic products (Mochizuki et al., 1988). Blanching with microwave energy has been reported to have advantages over conventional hot water or steam blanching by reduction of process times, energy and water usage and improvement of product quality (Ponne et al., 1994).Our objectives were to prepare pickled garlic using different processes (direct packing, packing after blanching with hot water, and packing after blanching with microwave energy) and to study changes in chemical characteristics, firmness and color during preparation and storage. MATERIALS & METHODS Preparation of pickled garlicFresh garlic bulbs were obtained from a market in Seville (Spain). After cracking the bulbs to separate the cloves and peeling the outer covering (Fig. 1), defective and smallest cloves were discarded. The remaining peeled cloves were washed with tap water and separated into three lots. One lot was directly packed into 10 " 8 Par" glass bottles (115g garlic cloves and 115 mL cover liquor capacity) using, as cover liquor, a brine (5% NACl) acidified with a lactic acid-acetic acid mixture. The concentration of each acid (0.74%, w/v) in the cover brine was calculated to give a pH of 4.0 after equilibrium between garlic cloves and brine. Half of the packed product (5 bottles) was pasteurized for 8 min in a water bath at 90°C (cover brine was added at Ϸ70°C) and the remainder was left as non-pasteurized control. All bottles were stored in a room maintained at 27 ± 2°C.A second lot of peeled garlic cloves was blanched in water at 90°C for 15 min and then packed. A portion of blanched-garlic cloves was packed into 10 "8 Par" glass bottles with the acidified cover brine used previously (added at ‫°07ف‬C). Five bottles were pasteurized at 90°C for 5.5 min and the rest left as non-pasteurized control. Both products were stored at 27 ± 2°C. The remaining portion of blanched garlic cloves was also packed with the same cover brine, except it was fortified with 0.27% potassium sorbate and 0.24% sodium benzoate, and maintained under refrigeration (4°C) during storage. The third lot of peeled garlic cloves was blanched usi...

Phytopathogenic fungal growth in postharvest fruits and vegetables is responsible for 20–25% of production losses. Volatile organic compounds (VOCs) have been gaining importance in the food industry as a safe and ecofriendly alternative to pesticides for combating these phytopathogenic fungi. In this study, we analysed the ability of some VOCs produced by strains of the genera Bacillus, Peribacillus, Pseudomonas, Psychrobacillus and Staphylococcus to inhibit the growth of Alternaria alternata, Botrytis cinerea, Fusarium oxysporum, Fusarium solani, Monilinia fructicola, Monilinia laxa and Sclerotinia sclerotiorum, in vitro and in vivo. We analysed bacterial VOCs by using GC/MS and 87 volatile compounds were identified, in particular acetoin, acetic acid, 2,3-butanediol, isopentanol, dimethyl disulphide and isopentyl isobutanoate. In vitro growth inhibition assays and in vivo experiments using cherry fruits showed that the best producers of VOCs, Bacillus atrophaeus L193, Bacillus velezensis XT1 and Psychrobacillus vulpis Z8, exhibited the highest antifungal activity against B. cinerea, M. fructicola and M. laxa, which highlights the potential of these strains to control postharvest diseases. Transmission electron microscopy micrographs of bacterial VOC-treated fungi clearly showed antifungal activity which led to an intense degeneration of cellular components of mycelium and cell death.

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