Fermentation lactic acid

Biacetyl is produced by the dehydrogenation of 2,3-butanediol with a copper catalyst (290,291). Prior to the availabiUty of 2,3-butanediol, biacetyl was prepared by the nitrosation of methyl ethyl ketone and the hydrolysis of the resultant oxime. Other commercial routes include passing vinylacetylene into a solution of mercuric sulfate in sulfuric acid and decomposing the insoluble product with dilute hydrochloric acid (292), by the reaction of acetal with formaldehyde (293), by the acid-cataly2ed condensation of 1-hydroxyacetone with formaldehyde (294), and by fermentation of lactic acid bacterium (295—297). Acetoin [513-86-0] (3-hydroxy-2-butanone) is also coproduced in lactic acid fermentation. 

Milchsaure, /. lactic acid, -ferment, n. lactic ferment, -garung, /. lactic fermentation. -pilz, m. lactic-acid bacillus, -salz, n. lactate. 

Effect of Pretreatment on Lactic Acid Fermentation of Bean Curd Refuse with Simultaneous Saccharification... 

Dry bean curd refuse was used as the substrate in the lactic acid fermentation with simultaneous saccharification (SSF). The dry bean curd refuse was preliminarily sieved under a mesh size of 250 II m. It contained 12.3% water, 4.0% ash, 0.8% lipid, 29.3% protein, 53.6% carbohydrate, respectively, in weight basis. The cellulase derived from Aspergilltis niger with an enzymatic activity of 25,000 units/g (Tokyo Kasei Industry Inc.) was employed as the saccharification enzyme. 

Lactic acid fermentation of HCl-pretreated bean curd refuse substrate with ESS... 

Table 1 shows the dry weight of substrate, and amounts of HCl aqueous solution for pretreatment, cellulase and suspension broth for the lactic acid fermentation with ESS. The initially supplied amount of bean curd refuse in dry weight basis was changed from 10 to 150 g to examine the influence of substrate loading. The amount of cellulase was increased against initial substrate loading. And also, the amoimt of 0.1 mol/1 HCl was increased against... 

Table 1 Operating condition in the lactic acid fermentation with SSF using HCl-pretreated substrate...

For lactic acid fermentation of bean curd refuse with simultaneous saccharification, it is found that the pretreatment of the substrate using 0.1 or 0.2 mol/l HCl aqueous solution with heating at niTi for 30 min efficiently solubilized the raw material and significantly enhanced the enzymatic saccharification followed by the lactic acid fermentation. The amount of initial load of bean curd refiise in dried state could be increased up to 75 g/1 in a batch fermentation, and the finally attained lactic acid yield and its concentration were as high as 87.0% and 45.8 g/1, respectively. 

Czyzowska, A., Klewicka, E., and Libudzisz, Z., The influence of lactic acid fermentation process of red beet juice on the stability of biologically active colorants, Eur. Food Res. TechnoL, 223, 110, 2004. 

Naouri et al. (1991) described another contained fluidized bed, the so-called high compacting multiphasic reactor (HCMR), which they used for malic and lactic acid fermentations for wine improvement. Bioparticles were contained within a tapered region and liquid was rapidly recycled through this region by pumping improved liquid/solid contact was cited as the advantage of this reactor. 

Davison, B. H., and Scott, C. D., A Proposed Bioparticle Fluidized-Bed for Lactic Acid Fermentation and Simultaneous Adsorption, Biotechnol. Bioeng., 39 365 (1992)... 

Sivakesava et al. also used Raman (as well as FT-IR and NIR) to perform a simultaneous on-line determination of biomass, glucose, and lactic acid in lactic acid fermentation by Lactobacillus casei.2 Partial least squares (PLS) and principal components regression (PCR) equations were generated after suitable wavelength regions were determined. The best standard errors were found to be glucose, 2.5 g/1 lactic acid, 0.7 g/1 and optical cell density, 0.23. Best numbers were found for FT-IR with NIR and Raman being somewhat less accurate (in this experiment). 

Fayolle et al. used a remote system to monitor on-line fermentations.15 Both the substrates (glucose, fructose, lactose, and galactose) and the metabolites (ethanol and lactic acid) were monitored. The equations used were built with PLS. The reference method was HPLC. For the alcohol fermentation, glucose, fructose, and ethanol had SEPs (in g/1) of 3.5, 4.5, and 3.8, respectively. For the lactic acid fermentation, the SEPs for lactose, galactose, and lactic acid were 4.1, 1.4, and 2.0, respectively. 

Lactic acid fermentation was the topic of a paper by Vaccari et al.35 In this work, lactic acid, glucose, and biomass were determined over the course of the reaction. The measurements were made in real time, using a bypass pump and flow-through cell for the NIR measurements. Instead of using normal chemomet-ric statistics, the authors used correlation coefficients, mean of differences, standard deviation, student s t-test, and the student test parameter of significant difference to evaluate the results. Under these restrictions, the results appeared fairly good, with the biomass having the best set of statistics. 

Uneviscerated salted mullet fish was a source of the outbreak (type E) in Egypt (Weber et ah, 1993). The level of carbohydrates in such products is usually too low for lactic acid fermentation. If the pH of the product is not low enough, it will not protect against the outgrowth of C. botulinum. 

Modern methods of livestock production are intensive and the environmental conditions stress the animals. The use of antibiotics promotes growth and protects the animals from otherwise certain infection under these conditions. Antibiotic-like compounds formed in lactic acid fermentations prevent proliferation of spoilage and pathogenic microorganisms and increase the shelf life of the products. Nisin is a antimicrobial produced by a lactic acid bacterium and is used in some countries as a food preservative. Some lactic acid bacteria are capable of favorably influencing the fecal flora in man and animals. 

Differentiation has been based on the main products of the fermentation. Generally, fermentation does not yield homogeneous products. For example, butyric acid is practically always accompanied by other fatty acids, both lower and higher in the series, as well as by alcohols, especially butanol, and by lactic acid. It may be noted that, according to Kempner and Kubowitz, fermentation can be transformed into lactic acid fermentation if the fermentation is carried out in an atmosphere of carbon monoxide. 

A practical technique for lactic acid fermentation of potato pulp has been developed (Oda et al., 2002). They screened 38 strains of the fungus Rhizopus oryzae either lactic acid or fumaric acid and ethanol were formed, and the ratio differed among the strains tested. Saito et al. (2003) studied the effect of pectinolytic enzymes on lactic acid fermentation of potato pulp by different Rhizopus oryzae NRRL 395 and NBRC 4707 strains. When a commercial preparation of pectinase was added to potato pulp inoculated with fungal spores and incubated for 7 days, both strains effectively produced larger amounts of lactic acid and ethanol. These data indicated that the fermentation of potato pulp depends on the degradation of pectic substances in NRRL 395 and NBRC 4707. Saito et al. (2006) evaluated the potato pulp obtained in different seasons and found pectin content to be dependent on the dates of extraction. 

Oda, Y, Saito, K., Yamauchi, H., Mori, M. (2002). Lactic acid fermentation of potato pulp by Ihe fungus Rhizopus oryzae. Curr. Microbiol., 45, 1. ... 

Saito, K., Kawamura, Y, Oda, Y. (2003). Role of the pectinolytic enzyme in the lactic acid fermentation of potato pulp by Rhizopus oryzae. J. Ind. Microbiol. BiotechnoL, 30,440 44. 

Having determined the effect of temperature and NaCl on koji autolysis, the next step in finding an optimal protocol for the rapid production of soy sauce with high flavor quality was to examine die effect of independent and combined effect of lactic acid fermentation and alcohol on koji autolysis. 

Effect of Lactic Acid Fermentation on Koji Autolysis. The effect of NaCl on lactic acid fermentation 10) is seen in Figure 5. Four autolysates were prepared... 

A new method for the preparation of soy sauce has been developed. The new scaled-up method divides the moromi process into two processes autolysis and fermentation. Because of the utilization of high temperatures, the new process permits the production of a NaCl free autolyzate from koji. Division of the fermentation process into two separated processes permit better control of lactic acid fermentation and alcohol fermentation processed which used to require great skill. The new scale-up procedure for soy sauce production yields a product in half the time required by the traditional (conventional) method and still produces a soy sauce with high levels of the desirable Bavor component, glutamic acid. Utilization of this protocol by the soy sauce producing industry should have significant economic impact to bo producers and consumers. 

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