Many of the spices and herbs used today have been valued for their antimicrobial effects and medicinal powers in addition to their flavor and fragrance qualities. Most of the foodbome bacterial pathogens examined were sensitive to extracts from plants such as cinnamon, clove, garlic, mustard, onion and oregano. me antimicrobial compounds in spices and herbs are mostly in the essential oil fraction. The Gram-positive bacteria were more sensitive to the antimicrobial compounds in spices than Gram-negarive bacteria. The extent of sensitivity varied with the strain and environmental conditions imposed. Certain spices can have a direct effect on the rate of fermentation by stimulating acid production in starter cultures. Phenols, alcohols, aldehydes, ketones, ethers and hydrocarbons have been recognized as major antimicrobial components in spices. m e antimicrobial activity and modes of actions of spices and their major antimicrobial components are reviewed. Percent Bacterial Inhibition Spice 75-100%Garlic, onion, allspice, oregano, thyme, cinnamon, tarragon, cumin, cloves, lemon grass bay leaf, capsicums, and rosemary 50-75 % Marjoram, mustard, caraway, mint, sage, fennel, coriander, dill, and nutmeg Less than 50 % Basil, parsley, cardamom, pepper (black and white) ginger, anise seed, celery seed, lemon, and lime 'Adapted from Billing and Sherman 1998.

Epiphytic LAB, e.g., lactobacilli, lactococci, enterococci, pediococci, streptococci, and leuconostocs, play a major role in silage fermentation. Their numbers and populations have become a concern in predicting the adequacy of silage fermentation and in determining whether or not to apply a bacterial inoculant (Bolsen et al, 1989). Epiphytic LAB counts are usually low and variable on silage crops (Lin et al, 1991), and increases in the LAB counts usually occur coincident to the chopping process. Only limited information is available concerning the succession of epiphytic LAB species during the ensiling period of alfalfa (Medicago sativaL.) and maize (Zea mays L.), the two major silage crops in North America. The present studies investigated the epiphytic LAB succession during the pre-ensiling and ensiling periods for two cuttings of alfalfa, each harvested at three stages of maturity, and three whole-plant maize hybrids.A second-year stand of alfalfa was harvested at the 2nd and 4th cuttings and at the late-bud, 10% bloom, and 50% bloom stages of maturity within each cutting in 1989. Following mowing, the alfalfa was wilted in the windrow for 5 to 6 hours prior to precision chopping.

1992. Epiphytic lactic acid bacteria (LAB) succession during the pre-ensiling and ensiling periods were studied in 1989 for two cuttings of alfalfa (Medicago sativa L.), each harvested at three stages of maturity, and three whole-plant maize (Zea mays L.) hybrids. Twenty-three species and 306 strains were found.Epiphytic LAB counts were low and variable on the standing crops, particularly on alfalfa. Wilting increased LAB numbers slightly for alfalfa, but the chopping process increased the counts dramatically. Population shifts in LAB also took place during the pre-ensiling period. Lactobacillus plantarum, Pediococcus pentosaceus, Enterococcus faecium, andEnt. faecalis were predominant on both standing crops. Lactobacillus brevis dominated alfalfa at the second cutting, 10% bloom, but Lact. viridescens was predominant after chopping. The changes in LAB caused by wilting or chopping were reflected mainly in proportional changes of Lact. plantarum, Ped. pentosaceus, Ent. faecium and Ent. faecalis. Once the crops were ensiled, total LAB counts increased rapidly, reached a maximum within 1 d, and then declined after 7 d of fermentation. Enterococcus species decreased sharply or disappeared entirely after the early stages of the ensiling period, and the species most involved in microbial succession through day 7 were Lact. plantarum and Ped. pentosaceus. After 7 d, more species, e.g. Lact. homohiochii, Lact. brevis and Lact. gasseri, joined the succession and became prevalent, depending on the crop. Only two of the six alfalfa silages were well preserved, whereas all three maize hybrids underwent typical fermentations for this crop. No relationship was found between adequacy of silage fermentation and epiphytic LAB numbers or species on the pre-ensiled crops. Neither were pH changes during the fermentation explained by the epiphytic LAB count or population succession. Rather, the well fermented alfalfa silages were those ensiled at a high dry matter (DM) content ( > 360 g/kg) and low buffering capacity ( < 450 meq/kg of DM). Only a few of the LAB strains were shown to be the same among the crops, thus indicating the specificity of LAB strains to an ecological niche.

Alkaline-fermented foods constitute a group of less-known food products that are widely consumed in Southeast Asia and African countries. They can be made from different raw ingredients. For instance, Japanese natto, Thai thua-nao, and kinema are made from cooked soybeans, dawadawa from African locust beans, ogiri from melon seeds, ugba from African oil beans, kawal from fresh legale leaves, owoh from cotton seeds, and pidan from fresh poultry eggs. In alkaline-fermented foods, the protein of the raw materials is broken down into amino acids and peptides; ammonia is released during the fermentation, raising the pH of the final products and giving the food a strong ammoniacal smell. Most alkaline fermentations are achieved spontaneously by mixed bacteria cultures, principally dominated by Bacillus subtilis. In other cases, pure cultures can be used. For example, Japanese natto is inoculated with a pure culture of B. subtilis var natto. Pidan is a special example of alkaline fermentation. Instead of using microorganisms, pidan is made using an alkali-treated fermentation. Sodium hydroxide (NaOH) is produced from the reaction of sodium carbonate (Na2CO3), water (H2O), and calcium oxide (CaO) of pickle or coating mud. NaOH penetrates into the eggs, causing the physicochemical changes, color changes, and gelation. The appearance of pidan differs from fresh eggs in that the white becomes a semitransparent tea-brown color, and the yolk is solid or semisolid with a dark-green color. The nutritional value of pidan is slightly decreased compared with fresh eggs, but pidan has an extremely long shelf life and a pleasant, fragrant taste that is preferred by most people in Southeast Asian countries. In a small-scale laboratory study conducted by the authors, B. subtilis was not found in pidan. Four Staphylococcus spp. (S. cohnii, S. epidermidis, S. haemolyticus, and S. warneri) and two strains of Bacillus spp. (B. cereus and B. macerans) were isolated from pidan. Staphylococcus spp. did not contribute to the fermentation and were considered contaminants.

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