Production of hard-type cheese using free or immobilized freeze-dried kefir cells as a starter culture

This study provides a contribution to hard-type cheese starter culture production through the use of a freeze-dried culture in the ripening of hard-type cheeses. The effect of initial cell concentration, ripening temperature, and cell immobilization of kefir on the degree of openness, mold spoilage, microbial associations, physicochemical characteristics, and aroma-related compounds was studied. Use of kefir starter cultures resulted in cheese with an increased shelf life and resistance to spoilage as compared to control cheeses without kefir inoculants. Furthermore, the freeze-dried kefir culture improved aroma, taste, and texture characteristics while increasing the degree of openness in comparison to traditional hard-type cheese products. The kefir culture resulted in an increase in counts of total aerobic bacteria, yeasts and molds, lactococci, and lactobacilli until the 15th day of ripening. From then on, only lactobacilli counts increased, reaching levels up to 9.17 log CFU/g in cheeses ripened at 5 degrees C using freeze-dried kefir cells immobilized on casein. SPME-GC/MS analysis revealed major differences in volatile composition, especially with regard to alcohols (up to 75%), carbonyl compounds (up to 75%), and esters (up to 64%) between cheeses made with kefir cells and cheeses made without kefir inoculants.     

Cytologic patterns of lymphadenopathy in canine monocytic ehrlichiosis

Background: Recognition of different cytologic patterns in lymph nodes (LNs) from dogs with canine monocytic ehrlichiosis (CME) and noninfectious causes of lymphoid reactivity may have diagnostic utility. Objectives: The aims of the present study were to compare cytologic patterns in LNs of dogs with different phases of CME, to investigate the association of cytologic pattern and presence of Ehrlichia spp. morulae, and to compare patterns of lymphoid reactivity between dogs with CME and those with noninfectious causes of lymphoid hyperplasia. Methods: Cytologic preparations of LNs from 35 dogs with nonmyelosuppressive CME (group A), 16 dogs with myelosuppressive CME (group B), 26 dogs with noninfectious diseases (group C), and 15 healthy dogs (group D) were evaluated. Percentages of lymphocyte types, plasma cells, macrophages, neutrophils, and eosinophils were determined. Samples from dogs in groups A and B were evaluated for the presence of morulae. Results: Cytologic abnormalities in LNs were recorded in 54% of dogs in group A, 88% in group B, 39% in group C, and 0% in group D and were more frequent (P=.02) in dogs with myelosuppressive CME than those with nonmyelosuppressive CME. Plasma cell hyperplasia was more frequent in CME than in noninfectious diseases (P=.03). An association between the presence of cytologic abnormalities and morulae in group A dogs was not found. Conclusions: Dogs with myelosuppressive CME have more lymphoid cytologic abnormalities than dogs with nonmyelosuppressive CME. LN plasmacytosis is the major pattern of lymphadenopathy in dogs with CME and is found more frequently in dogs with CME than in dogs with noninfectious causes of lymphadenopathy.     

Continuous whey fermentation using kefir yeast immobilized on delignified cellulosic material

Delignified cellulosic-supported biocatalyst, prepared by immobilization of kefir yeast on delignified cellulosic material (DCM), was found to be suitable for continuous, modified whey fermentation. The modified whey contained 1% raisin extract and molasses. Ethanol productivities ranged from 3.6 to 8.3 g L(-1)day(-1), whereas parameters such as ethanol concentration, residual sugars, and daily fermented whey productivity were acceptable for the production of potable alcohol and alcoholic drinks in industrial fermentations. The continuous fermentation bioreactor was operated for 39 days, stored for 18 days at 4 degrees C, and operated again for another 15 days without any diminution of the ethanol productivity. The concentrations of higher alcohols (propanol-1, isobutyl alcohol, and amyl alcohols) were low. The main volatile byproducts formed in the continuous process were similar to those observed in alcoholic beverages, and the fermented whey had a good aroma. The concentrations of higher alcohols were very low when compared to that of ethyl acetate, therefore resulting in a quality product. The possibility of using such a process for the production of potable alcohol or a novel, low-alcohol content drink is proposed.     

Low-temperature brewing by freeze-dried immobilized cells on gluten pellets

A biocatalyst, prepared by the immobilization of a cryotolerant strain of Saccharomyces cerevisiae on gluten pellets, was freeze-dried without any protecting medium and used for repeated batch fermentations of wort for each of the temperatures 15, 10, 5, and 0 degrees C. The fermentation time for freeze-dried immobilized cells was about 2-fold that of the corresponding time for wet immobilized cells on gluten pellets, and lower than the corresponding time for freeze-dried free cells, especially at 5 and 0 degrees C. Beers produced by freeze-dried immobilized cells contained alcohol levels in the range of 5.0-5.5% v/v, diacetyl concentrations lower than 0.5 mg/L, polyphenol concentrations lower than 145.5 mg/L, and free cell concentrations lower than 3 g/L. As a result, they had a very good clarity after the end of primary fermentation. The amounts of amyl alcohols were lower than 129.1 mg/L and reduced as the temperature was decreased. Ethyl acetate concentrations were found in the range of 22.1-29.2 mg/L, giving a very good aroma and taste in the produced beers.     

Low-temperature brewing using yeast immobilized on dried figs

Dried figs, following exhaustive extraction of their residual sugars with water, were used for immobilization of Saccharomyces cerevisiae AXAZ-1. The immobilized biocatalyst was used in repeated batch fermentations of glucose at 30 degrees C, where significant reduction of the fermentation time was observed, falling from 65 h in the first batch to 7 h after the sixth batch. Repeated fermentations of wort at room and low temperatures resulted in fermentation times that fell from 26 to 20 h and from 27 to 24 days at 18 and 3 degrees C, respectively. Ethanol and beer productivities were high, showing suitability of the biocatalyst for low-temperature brewing. Diacetyl concentrations were low (0.3-0.5 mg/L), and polyphenols were lower than in commercial products and decreased as the fermentation temperature was decreased (126-50 mg/L). Ethyl acetate concentrations increased from 53 to 88 mg/L as the temperature was decreased, while the concentration of amyl alcohols at 3 degrees C (58 mg/L) was lower than half of that at 18 degrees C (125 mg/L). The beers produced at the end of the main fermentation had a fine clarity and a special fruity figlike aroma and taste, distinct from commercial products and more intense than beers produced by cells immobilized on other food-grade supports (gluten pellets or delignified cellulosic materials). GC-MS analysis did not show significant differences in the qualitative composition of the aroma compounds of the beers produced by immobilized and free cells.     

Evolution of volatile byproducts during wine fermentations using immobilized cells on grape skins

A biocatalyst was prepared by immobilization of Saccharomyces cerevisiae cells on grape skins. Repeated batch fermentations were conducted using this biocatalyst as well as free cells, at 25, 20, 15, and 10 degrees C. Solid phase microextraction (SPME) was used in monitoring the evolution of volatile byproducts. The effect of immobilization and temperature on evolution patterns of volatiles was obvious. The major part of esters was formed after consumption of 40-50% of the sugars. Similar processes were observed for amyl alcohols and 2-phenylethanol, whereas 1-propanol and 2-methyl-1-propanol were formed during the whole alcoholic fermentation period at an almost constant formation rate. Acetaldehyde and acetoin were synthesized in the early stages of fermentation. Afterward, their amount decreased. In most cases, immobilized cells exhibited higher formation rates of volatiles than free cells. The final concentration of esters was higher in wines produced by immobilized biocatalyst. Their amount increased with temperature decrease. The opposite was observed for higher alcohols.     

Mantle discontinuity structure beneath the southern east pacific rise from P-to-S converted phases

Receiver functions derived from teleseismic body waves recorded by ocean-bottom seismometers on the southern East Pacific Rise reveal shear waves converted from compressional waves at the mantle discontinuities near 410- and 660-kilometer depth. The thickness of the mantle transition zone between the two discontinuities is normal relative to the global average and indicates that upwelling beneath the southern East Pacific Rise is not associated with an excess temperature in the mantle transition zone.     

Serum alkaline phosphatase isoenzyme activities in canine malignant mammary neoplasms with and without osseous transformation

BACKGROUND: Increased serum activity of total alkaline phosphatase (TALP) has been found in dogs with mammary neoplasms, especially malignant mixed tumors. We hypothesized that the bone isoenzyme of alkaline phosphatase (BALP), a specific indicator of osteoblastic activity and bone formation, may contribute to increased TALP in dogs with mammary neoplasms with osseous transformation. OBJECTIVE: The purpose of this study was to compare serum TALP, BALP, and other ALP isoenzyme activities in dogs with mammary malignant neoplasms with and without osseous transformation. METHODS: Twenty-one female dogs with malignant mammary neoplasms were compared with 21 clinically healthy, age-matched female control dogs. Physical, clinicopathologic (including preprandial and postprandial serum bile acids, ACTH stimulation, and low-dose dexamethasone suppression tests), radiographic, and ultrasonographic examinations were performed on all dogs with tumors to assess coexisting conditions. On the basis of histologic examination of excised tumors, dogs were further classified as having epithelial (n = 11) or mesenchymal/mixed (epithelial-mesenchymal) (n = 10) neoplasms, the latter of which had histologic and radiologic evidence of bone formation. Serum TALP, BALP, liver alkaline phosphatase (LALP), and corticosteroid-induced alkaline phosphatase (CALP) activities were measured using biochemical methods. RESULTS: Dogs with malignant mammary tumors had significantly higher (P < .05) median serum TALP (170 U/L), BALP (59 U/L), LALP (49 U/L), and CALP (24 U/L) activities, compared with control dogs (81, 32, 37, and 5 U/L, respectively). Significantly higher activities of BALP and LALP were found in dogs with epithelial neoplasms; whereas, only CALP activity was higher in dogs with mesenchymal/mixed neoplasms. There was no significant difference in TALP or isoenzyme activitities between epithelial and mesenchymal/mixed groups. CONCLUSION: BALP activity is increased in some dogs with malignant mammary tumors but does not account for the increase in TALP in dogs with neoplasms that have osseous transformation.