Red-Veined Cheese is an experimental internal mold-ripened cheese using red koji powder as the red starter. The objective of this study was to characterize the physicochemical parameters, microorganisms, proteolysis, lipolysis, and volatile profile of the cheese during 33 days of ripening. The gross composition was 56.7% (w/w) for total solids, 45.8% (w/w) for fat-in-dry matter, 2.58% (w/w) for salt content and 37.8% (w/w) for protein. The pH increased from 4.88 to 5.23 during ripening. The Monascus density first rose and then fell, while total mesophilic bacteria count declined steadily throughout the maturation. Proteolysis degree in experimental group was significantly higher than in control group without inoculation of red koji powder. Analysis of the fatty acid profile showed that the internal Monascus-fermentation also promoted lipolysis. A total of 63 volatile compounds, including 12 ketones, 14 alcohols, 15 acids, 13 esters, 5 aldehydes, 3 lactones and 1 phenol, were identified by gas chromatography-mass spectrometry (GC–MS) coupled with headspace solid-phase microextraction (HS-SPME). The main chemical groups of volatile compounds were ketones, alcohols, acids and esters whereas aldehydes, lactones, and phenols represented only minor components. At the end of ripening, the levels of ketones, alcohols, esters were significantly higher in the experimental cheese compared with the control. Our results therefore show that the internal Monascus-fermentation is not only a suitable technology to form red veins in the paste but also an effective method to impact the composition of volatile compounds in cheese, which can thus distinguish it from other internal mold-ripened cheeses and surface-ripened Monascus-fermented cheese.

At present, De Man, Rogosa and Sharpe (MRS) broth is the medium of choice for promoting bacteriocin production. However, this medium is expensive and not applicable for large-scale production. Therefore, a low-cost and high-efficiency culture medium for bacteriocin Lac-B23 production by Lactobacillus plantarum J23 was developed. First, the effects of the composition of MRS broth on bacteriocin Lac-B23 production and bacterial growth were researched by a one variable at a time approach. Then, a Plackett-Burman design was used to screen significant components for production. Finally, the steepest ascent and central composite designs were used to obtain an optimum medium. The final composition of the modified MRS was much simpler than MRS broth, and the modified MRS contained only glucose, yeast extract, dipotassium phosphate, manganese sulfate monohydrate, Tween 80 and sodium acetate anhydrous. The highest bacteriocin Lac-B23 production reached 2560 activity units (AU)/mL in the modified MRS, which is nine times higher than that in MRS broth (280 AU/mL). Meanwhile, the cost per liter of the modified MRS (8.56 Ren Min Bi (RMB)/L) is 34.70% the cost of MRS broth (13.11 RMB/L), and the cost per arbitrary units of bacteriocin Lac-B23 in the modified MRS is approximately fourteen times more convenient (3.34 RMB/106 AU) than in the MRS broth (46.82 RMB/106 AU).

Lactic acid bacteria (LAB) are a prevalent bacterial group in rice wine maturation that contributes to flavor, texture, and nutritive value. To better understand LAB diversity in rice wines, 6 rice wine varieties from different regions in China were investigated using denaturing gradient gel electrophoresis (DGGE). , and were identified using DGGE. Forty nine isolates were screened using a culture-dependent method. Prominent taxa were identified as Enterococcus sp., , and. Isolates were grouped and used for fermentation of rice wines. Greater numbers of species involved in fermentation lead to better sensory attributes of wine. DGGE analysis combined with a culture-dependent method can be a tool for investigation of the bacterial compositions of fermented rice wines.

No abstract

Rice wine is a fermented beverage with high nutritious value and popular among most of Asian countries, including China, Korea, Japan, India and Thailand. Rice wine is mainly made from glutinous rice, grain or cereal, but with different name and material in different country, such as sweet fermented rice or yellow wine in China, sake in Japan and Ruou in Viet Nam. Even so, rice wine has a similar fermented process inherited from ancestors. Most rice wines are fermented under the natural circumstances with interaction of fungi, yeast and bacteria especially lactic acid bacteria, which is a complicated procedure 1-6. After the fermentation from grain or cereal, the production was obtained with non-filtration, filtration or distillation. In China, some kinds of rice wine with distillation, such as Kaoliang with a higher alcoholic content, which can reach to 40 % by volume. Otherwise, we call the wine without distillation as "yellow wine" and the ethanol content ranges up to 20 % by volume. Sometimes, there is fermented residue left in rice wine and only fermented for a couple of days. These rice wines are not deep fermented, which means they are fresh. We also called them sweet fermented rice or "Laozao" in China. The sweet fermented rice has a lower alcoholic content about 5 % by volume.