An Investigation of the Use of the MicroFoss as an Indicator of the Shelf Life of Pasteurized Fluid Milk

The MicroFoss method was evaluated for its effectiveness as an indicator of fluid milk shelf life. Half-gallon, 2% fat fluid milk samples (n = 90) were obtained from a milk processing plant on 3 occasions postpasteurization and evaluated for shelf life. Sensory evaluation was performed by 3 judges experienced in the use of the American Dairy Science Association scorecard for milk. A score of 5 or less was considered to represent the end of the shelf life of the product. MicroFoss coupled with preliminary incubation (PI) was utilized to estimate the total viable (TVC) and gram-negative counts (GN) in the milk. The MicroFoss functions by using a pH indicator or CO2 production to detect changes in light reflection to estimate bacterial populations. Simple and multiple linear regression analyses were utilized to determine the relationship between MicroFoss (PI-GN and PI-TVC detection times) and product shelf life. It was concluded that using both PI-GN and PI-TVC in a combined algorithm is the optimal way of using MicroFoss as a shelf-life indicator. When PI-TVC was selected in the algorithm, a correlation coefficient of 0.89 existed between PI-TVC and shelf life; PI-GN was used in the algorithm in the place of PI-TVC when its detection time was within 6 h of the detection time of PI-TVC vials. The PI-GN detection times correlated well (r = 0.80) with shelf life, but more importantly, all but one PI-GN sample (n = 50) selected in the algorithm had a shelf life of less than 10 d. This indicates that the PI-GN measurement can be utilized along with PI-TVC detection time to indicate potential shelf-life problems.

Transmyocardial laser revascularization causes sustained VEGF secretion

Transmyocardial laser revascularization (TMR) using a carbon dioxide (CO(2)) laser has been shown to relieve angina, increase vascular density, and improve myocardial contraction. A study of 28 patients receiving TMR was conducted to monitor vascular endothelial growth factor (VEGF) levels with the goal of clarifying the relationship between TMR, the amelioration of angina, and vascular density. Serum VEGF levels were measured during four periods (preoperative, postoperative, convalescence, and late) in these 28 patients who received sole therapy TMR for un-revascularizable ischemic angina and the levels were compared with the control group consisting of 10 nonischemic thoracotomy patients. Twelve of the 28 patients had previous coronary artery bypass graft(s); 10 had unstable angina, and 1 had an ejection fraction less than 30%. Overall, angina class was reduced from 3.8 +/- 0.9 to 1.0 +/- 0.9 (P < 0.01) at the 1-year follow-up. There were no perioperative mortalities; however, there was one late mortality. The results show that VEGF levels were higher in the convalescence and late periods. Specifically in the late period, VEGF levels in TMR therapy patients surpassed those of the control group and normalized VEGF levels were three times higher in the late period than preoperatively. The sustained VEGF secretion observed in this study may help to explain why CO(2) TMR therapy causes locally increased vascular density and angina relief.

Clampless Anastomosis: Novel Device for Clampless Proximal Vein Anastomosis in OPCAB Surgery--The Initial Spyder Experience

The Spyder is a novel device that enables the attachment of a vein to the aorta by compliant, interrupted anastomosis; this minimizes aortic manipulation during off pump-coronary artery bypass (OPCAB) surgery. Its use may reduce transcranial Doppler signals recorded during CABG. We performed 250 anastomoses in 160 OPCAB cases in many centers and recorded efficiency and efficacy data. There were no adverse events noted during the operative period. In a subset of patients in one center, flow (n = 48) and transcranial Doppler signals (n = 22) were measured. We found the device to be a useful adjunct for minimally invasive CABG surgery.

A novel device for clampless proximal anastomosis in OPCAB surgery: the IPAD

The Coalescent IPAD (Coalescent Surgical, Sunnyvale, CA, USA) is a novel device that enables creation of a compliant proximal vein anastomosis to the aorta during off-pump coronary artery bypass (OPCAB) surgery while reducing the risk of cerebrovascular emboli and early stenosis. We performed IPAD-created anastomoses in 76 patients having standard OPCAB surgery. Following the procedures, no patients developed myocardial infarctions or reported angina, suggesting patency of the vein grafts to be of high quality. We found the device to be a useful adjunct for minimally invasive CAB graft surgery.

Influence of adjunct cultures on volatile free fatty acids in reduced-fat Edam cheeses

The effects of the adjunct cultures Lactococcus lactis ssp. diacetylactis, Brevibacterium linens BL2, Lactobacillus helveticus LH212, and Lactobacillus reuteri ATCC 23272 on volatile free fatty acid production in reduced-fat Edam cheese were studied. Lipase activity evaluation using p-nitrophenyl fatty acid ester substrates indicated that L. lactis ssp. diacetylactis showed the highest activity among the 4 adjunct cultures. Full-fat and 33% reduced-fat control cheeses (no adjunct) were made along with 5 treatments of reduced-fat cheeses, which included individual, and a mixture of the adjunct cultures. Volatile free fatty acids of cheeses were analyzed using static headspace analysis with 4-bromofluorobenzene as an internal standard. Changes in volatile free fatty acid concentrations were found in headspace gas of cheeses after 3-and 6-mo ripening. Acetic acid was the most abundant acid detected throughout ripening. Full-fat cheese had the highest relative amount of propionic acid among the cheeses. Certain adjunct cultures had a definite role in lipolysis at particular times. Reduced-fat cheese with L. lactis ssp. diacetylactis at 3-mo showed the highest levels of butyric, isovaleric, n-valeric, iso-caproic, and n-caproic acid. Reduced-fat cheese with Lactobacillus reuteri at 6 mo produced the highest relative concentration of isocaproic, n-caproic, and heptanoic, and the highest relative concentration of total acids.

Effect of Pressure and Fat Content on Particle Sizes in Microfluidized Milk

Average diameters and particle size distributions in fluid milks with different fat contents and subjected to various homogenization pressures with a "microfluidizer" were evaluated. Skim, 2%, and whole milks were microfluidized at 50, 100, 150, and 200 MPa. Cream containing 41% milk fat was microfluidized at 50, 100, and 150 MPa. Particle sizes were determined by laser light scattering. As microfluidization pressure was increased from 50 to 100 MPa, particle sizes in skim, 2%, and whole milks decreased. Microfluidization at pressures greater than 100 MPa had little additional effect on reducing the particle sizes in skim and 2% milks compared with microfluidization at 100 MPa, but the particle sizes in whole milk increased as the microfluidization pressure was increased from 100 to 200 MPa due to formation of homogenization clusters. The particle sizes in cream increased as the microfluidization pressure was increased from 50 to 150 MPa. When the microfluidization pressure was held constant, the particle sizes increased as the milk fat concentration was increased. The coefficients of variations of the volume-weighted particle size distributions for cream were higher than for skim, 2%, and whole milks. Larger "big" particles and smaller "small" particles were formed in whole milk after microfluidization at 200 MPa than at 100 MPa. Although microfluidization can be used to produce small particles in skim, 2%, and whole milks, a higher than optimum pressure (above 100 MPa) applied to whole milk will not lead to the minimum d(43) (volume-weighted average diameter) due to formation of clusters.

Interrupted distal anastomosis: the interrupted “porcupine” technique

The distal coronary artery bypass graft anastomosis created by an interrupted technique using nitinol clips is likely superior to that created with continuous suture because surgeons place clips with optimal visualization, and the anastomosis exhibits optimal compliance and cannot become a "purse-string" once constructed. Skillful use of the clips allows the surgeon to work in the ever more cramped quarters of the minithoracotomy or minimally invasive incision. Anastomosing vessels without knot tying is a valuable practice in the application of remote and robotic surgeries.

Properties of frozen dairy desserts processed by microfluidization of their mixes

Sensory properties and rate of meltdown of nonfat (0% fat) and low-fat (2% fat) vanilla ice creams processed either by conventional valve homogenization or microfluidization of their mixes were compared with each other and to ice cream (10% fat) processed by conventional valve homogenization. Mixes for frozen dairy desserts containing 0, 2, and 10% fat were manufactured. Some of the nonfat and low-fat ice cream mixes were processed by microfluidization at 50, 100, 150, and 200 MPa, and the remaining nonfat and low-fat ice cream mixes and all of the ice cream mix were processed by conventional valve homogenization at 13.8 MPa, first stage, and 3.4 MPa, second stage. The finished frozen and hardened products were evaluated at d 1 and 45 for meltdown rate and for flavor and body and texture by preference testing. Nonfat and low-fat ice creams that usually had a slower meltdown were produced when processing their mixes by microfluidization instead of by conventional valve homogenization. Sensory scores for the ice cream were significantly higher than sensory scores for the nonfat and low-fat ice creams, but the sensory scores for the conventional valve homogenized controls for the nonfat ice cream and low-fat ice cream were not significantly different from the sensory scores for the nonfat ice cream and low-fat ice cream processed by microfluidization of the mixes, respectively. Microfluidization produced nonfat and low-fat ice creams that usually had a slower meltdown without affecting sensory properties.

Influence of adjunct cultures on ripening of reduced fat Edam cheeses

The influence of four adjunct cultures [Brevibacterium linens (BL2), Lactococcus lactis ssp. diacetylactis, Lactobacillus helveticus (LH212), and Lactobacillus reuteri (ATCC 23272)] on chemical and sensory characteristics of reduced fat Edam cheese was studied. The aminopeptidase activity of Lactococcus lactis ssp. diacetylactis was higher than that of Lactobacillus helveticus, Lactobacillus reuteri, and Brevibacterium linens, respectively. Mean percent fat and moisture contents of reduced fat cheese were 20.85 +/- 0.69 and 42.95 +/- 0.43, respectively. Percentage of fat and moisture of full fat control cheese were 30.06 +/- 0.78 and 39.11 +/- 0.60. Titratable acidity increased in all cheese with aging while pH initially decreased but increased in cheese after 6 mo aging at 7 degrees C. Lactic acid bacteria counts were on average one log higher for reduced fat cheeses than for full fat control cheese and counts decreasing with aging. Free amino acids (FAA) in cheeses increased with aging, and were higher in reduced fat cheeses than in the full fat control cheese. Reduced fat cheeses containing L. helveticus exhibited the highest FAA content. Descriptive sensory panelists (n = 9) did not detect differences among cheeses after 3 and 6 mo ripening, but aged/developed flavors (fruity, nutty, brothy, sulfur, free fatty acid) and sweetness increased between 3 and 6 mo. Expert panelists (n = 6) detected differences in texture quality among the cheeses. Reduced fat control cheeses and reduced fat cheeses with L. helveticus and L. reuteri received the highest texture quality scores. Addition of L. helveticus and Lc. lactis ssp. diacetylactis, as adjunct cultures to reduced fat Edam cheeses increased proteolysis, while the addition of L. helveticus and L. reuteri increased texture quality of cheeses.

Formulations and processing of yogurt affect the microbial quality of carbonated yogurt

Carbonation, flavor, culture type, pH, and storage time were varied to investigate the effects of these variables and their interactions on the growth of both typical and nontypical yogurt cultures and some contaminating bacteria. Two types of yogurt cultures (YC-470 and YC-180) were used as the source of typical yogurt bacteria, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. In addition, Lactobacillus acidophilus (LA-K) and Bifidobacterium longum ATCC 15707 were added as nontypical yogurt cultures to make sweetened low fat (1%) Swiss-style plain, strawberry, and lemon yogurts. Samples were incubated at 43 degrees C until pH values of 5.0 or 4.2 were reached. Strawberry yogurts at low (4.2) and high (5.0) pHs were divided into three portions, which were separately inoculated with contaminating bacteria, Bacillus licheniformis ATCC 14580, Escherichia coli ATCC 11775, and Listeria monocytogenes Scott A. After incorporation of carbon dioxide (1.10 to 1.27 volume of CO2 gas dissolved in water), the yogurt was stored at 4 degrees C for a 90-d period. Carbon dioxide did not affect the growth of typical or nontypical yogurt bacteria. Also, CO2 did not inhibit the growth of undesirable microorganisms. In general, low levels of CO2 did not affect the bacterial population in yogurt. The microflora of yogurt were influenced by culture type, pH, flavor type, and storage time or their interactions.

Listeria monocytogenes, Yersinia enterocolitica, and Salmonella in dairy plant environments

In order to determine the presence of the three environmental pathogens in dairy plants, six milk and four ice cream plants in a three state area were sampled. A total of 353 environmental samples were taken over three replications. Bacterial counts were performed on the environmental samples for chi-square analysis. Salmonella spp. were not isolated from any of the environmental samples. Yersinia enterocolitica was isolated from 6.8% of the environmental samples. Listeria monocytogenes was isolated from 6.5% of the environmental samples. Listeria spp. other than L. monocytogenes were isolated from 9.3% of the environmental samples. The presence of Y. enterocolitica was significantly related to high bacterial counts for six microbiological tests. The presence of L. monocytogenes was not related to high bacterial counts.

Helping employees and families cope with breast cancer treatment

With respect to a lump in the breast, all findings can be considered significant until necessary evaluation is completed. Persons who have cancer often attribute all symptomatology to the disease; therefore, the nurse needs to allay fears about commonly occurring illnesses, while staying attuned to indications of metastasis. Keeping up-to-date with a rapidly changing field will be a challenge to nurses in the position to counsel and to have a positive effect on the lives of millions of women with or at risk for breast cancer. The occupational health nurse is in a strategic position to encourage prevention and surveillance, as well as to counsel employees during diagnosis, treatment, and rehabilitation.

Clinical experience with ciprofloxacin: analysis of a multi-practice study

In a multi-practice study of 113 patients treated with ciprofloxacin (mean daily dosage, 995 mg per day; mean duration of treatment, 9.6 days) for a variety of infections, 14 were microbiologically proven. Of these, bacteriologic cure and/or improvement resulted in 92.9% of cases. For all 113 infections, clinical cure and/or improvement resulted in 97.1% of cases. A total of 17 infections were classified as chronic. Therapy with ciprofloxacin was discontinued in three (2.6%) of 113 patients because of adverse effects. Overall, there were 5/113 (4.4%) adverse reactions (ADRs). Only one ADR was related definitely to ciprofloxacin therapy. Two ADRs were definitely not related; in two the relationship was uncertain. Two patients of the five (40%) elected to continue ciprofloxacin therapy despite mild side effects.

Assessment of Dairy Product Quality and Potential Shelf-Life - A Review

Over the years, many tests and assays have been developed to estimate the quality and potential shelf-life of dairy products. These have ranged from simple, standard bacterial enumerations to more complex metabolite detections. This paper is a review of the parameters that have been used to estimate, or indicate the inherent quality of dairy products.

Estimation of Potential Shelf Life of Cottage Cheese Utilizing Bacterial Numbers and Metabolites

A study was conducted to investigate the use of bacterial numbers and their metabolites as estimators of the potential shelf life of cottage cheese. Dry cottage cheese curd and cream dressing were obtained on the day of processing. Portions of the cream dressing were inoculated with Pseudomonas fluorescens P27 to result in approximate levels of 0, 1,000 and 100,000 bacteria per g in finished cottage cheese after combining the curd and cream. Samples, stored at 7°C, were sensorially evaluated on a daily basis and analyzed every 7 d for up to 35 d. On days of analysis each sample was subjected to preliminary incubation (PI) as follows: none, 21°C for 7 h, 21°C for 14 h, 13°C for 18 h and 18°C for 18 h. For each PI, samples were enumerated by aerobic plate count, modified psychrotrophic bacteria count and gram-negative (CVT) count. Samples were enumerated for the standard psychrotrophic bacteria count without PI. Samples were also exposed to 18°C for 18 h PI in plate count broth for impedance detection measurements. Endotoxin (lipopolysaccharide) concentration and proteolysis were determined by the Limulus amebocyte lysate assay and the o-phthaldialdehyde method, respectively. Bacterial enumerations proved to be of little estimative value as the highest correlation coefficient obtained was -0.61. Endotoxin, proteolysis and impedance detection methods resulted in high correlation coefficients as related to potential shelf life of cottage cheese, with values of -0.81, -0.87 and -0.90, respectively. A prediction equation was formulated from the data.

Estimation of Potential Shelf-life of Pasteurized Fluid Milk Utilizing Bacterial Numbers and Metabolites

A study was conducted on use of bacterial numbers and their metabolites, and any possible interaction thereof, as estimators of the potential shelf-life of pasteurized fluid milk. Whole and skim milk samples were obtained on the day of processing. Samples of each milk were inoculated in duplicate with 0, 1,000, or 100,000 bacteria/ml with a pure strain of Pseudomonas fluorescens P27. Samples, stored at 7°C, were analyzed for microbiological and bioichemical parameters every 5 d for up to 20 d, with organoleptic evaluations conducted on a daily basis. On days of analysis, each sample was subjected to various preliminary incubations. Bacterial enumerations conducted were psychrotrophic bacteria count, standard plate count, gram-negative bacteria count, and modified psychrotrophic bacteria count. Lipopolysaccharide (endotoxin) concentrations, degree of proteolysis and impedance detection were also determined. All bacterial enumerations and proteolysis were significantly related to potential shelf-life of pasteurized fluid milk (whole, skim, and combined) but were of little predictive value. Endotoxin concentration and impedance detection were highly significantly related to shelf-life, and provided predictive regression equations. Using combined data from whole and skim milk, impedance detection resulted in the preferred prediction equation suitable for pasteurized fluid milks.

Antibiotic Residue Detection in Milk - A Review

Methods for antibiotic residue detection in dairy products, especially raw milk, have greatly improved as to their rapidity, accuracy and sensitivity over the past 30 years. An assay requiring overnight coagulation was available in the mid-1950's, whereas now there is an immunologically-based test using monoclonal antibody technology requiring only 6 min. These advances have not come about without extensive research efforts. The following is an overview of the developments and their significance to the dairy industry.

Rapid Impedimetric Method for Determining the Potential Shelf-Life of Pasteurized Whole Milk

Potential shelf-life of 100 pasteurized whole milk samples, obtained from retail outlets and from dairy processors, was investigated. Parameters studied were: organoleptic evaluation, Standard Plate Count (SPC), psychrotrophic bacteria count (PBC), modified psychrotrophic bacteria count (mPBC), Moseley test (MSPC), and impedance detection time (IDT) at 18 and 21°C. Correlation coefficients were obtained for all possible data combinations in an attempt to detect significant relationships between the parameters studied and the true shelf-life of the product. None of the direct counts (SPC, PBC, and mPBC) correlated well enough with shelf-life to allow shelf-life prediction. Moseley test (MSPC) appeared to possess an adequate relationship to shelf-life with a correlation coefficient at -0.84. IDT 21°C and IDT 18°C proved to have the most significant relationships to shelf-life with correlation coefficients of 0.88 and 0.87, respectively. Therefore, the impedance method had three advantages over the Moseley test: (a) it was a better predictor of shelf-life, (b) it was less labor intensive, and (c) it required only 1-2 d, as opposed to 7-9 d to complete.

Preliminary Incubation Count as an Index of Raw Milk Microbiological Quality During Storage

During a 5-month period, 200 raw milk samples were collected from two Louisiana milk plants. Standard Plate Count (SPC), Psychrotrophic Bacteria Count (PBC), and Proteolytic Count (PC) of each sample were initially determined, then monitored daily during a 5-d storage period at 2.2°C. As hypothesized, all bacterial counts increased during the storage period. The magnitude of the increase in bacterial numbers during storage was further investigated by dividing the milk samples into bacteriologically acceptable and unacceptable groups based on SPC or Preliminary Incubation (PI) count. An SPC of 1.0 × 10⁵/ml and PI counts of 1.0 × 10⁵/ml, 1.5 × 10⁵/ml, 2.3 × 10⁵/ml, and 3.0 × 10⁵/ml were used to repeatedly dichotomize the 200 raw milk samples into two groups. Median SPC, PBC, and PC for each acceptable and unacceptable group were then calculated. Dichotomization based on PI counts yielded acceptable sample groups having consistently lower bacterial counts during storage than did the acceptable sample group, which resulted from the dichotomization based on a SPC of 1.0 × 10⁵/ml. The results of this study indicated that the PI count is of considerable value for raw milk quality control.