Ultraviolet A and B wavelength-dependent inactivation of viruses and bacteria in the water.

UVA and UVB can be applied to solar disinfection of water. In this study, the inactivation and photoreactivation of viruses and bacteria in the UVA-B range were analyzed. MS2 and T4 bacteriophages, and Escherichia coli were used as surrogates to quantify dose-response behaviors. Inactivation in UVC was used to validate the methodology and to expand the inactivation action spectra. The results showed log-linear inactivation for MS2 and T4 in the 254-320 nm wavelength range. T4 inactivation was consistently faster than MS2 (except at 320 nm), and for both phages, inactivation decreased with increasing wavelength. The dose-response of bacteria exhibited a lag at low doses, possibly because the photons must strike a discrete number of critical targets before growth stops. A tail was present at high doses for some wavelengths, perhaps due to clumping or the presence of subgroups with higher resistance. The inactivation action spectra for bacteria exhibited a reduction in inactivation as wavelength increased. No bacterial inactivation was observed beyond 320 nm at doses applied. After inactivation at 297 nm (UVA), bacteria regained viability through photoreactivation, and repair increased with increase in photoreactivating light exposure time. This implies additional doses above inactivation thresholds are required to cause irreversible damage. These results are useful for designing solar disinfection systems.

Pharmacogenomics-Based Point-of-Care Clinical Decision Support Significantly Alters Drug Prescribing.

Changes in behavior are necessary to apply genomic discoveries to practice. We prospectively studied medication changes made by providers representing eight different medicine specialty clinics whose patients had submitted to preemptive pharmacogenomic genotyping. An institutional clinical decision support (CDS) system provided pharmacogenomic results using traffic light alerts: green = genomically favorable, yellow = genomic caution, red = high risk. The influence of pharmacogenomic alerts on prescribing behaviors was the primary endpoint. In all, 2,279 outpatient encounters were analyzed. Independent of other potential prescribing mediators, medications with high pharmacogenomic risk were changed significantly more often than prescription drugs lacking pharmacogenomic information (odds ratio (OR) = 26.2 (9.0-75.3), P < 0.0001). Medications with cautionary pharmacogenomic information were also changed more frequently (OR = 2.4 (1.7-3.5), P < 0.0001). No pharmacogenomically high-risk medications were prescribed during the entire study when physicians consulted the CDS tool. Pharmacogenomic information improved prescribing in patterns aimed at reducing patient risk, demonstrating that enhanced prescription decision-making is achievable through clinical integration of genomic medicine.

Patient Perceptions of Care as Influenced by a Large Institutional Pharmacogenomic Implementation Program.

Despite growing clinical use of genomic information, patient perceptions of genomic-based care are poorly understood. We prospectively studied patient-physician pairs who participated in an institutional pharmacogenomic implementation program. Trust/privacy/empathy/medical decision-making (MDM)/personalized care dimensions were assessed through patient surveys after clinic visits at which physicians had access to preemptive pharmacogenomic results (Likert scale, 1 = minimum/5 = maximum; mean [SD]). From 2012-2015, 1,261 surveys were issued to 507 patients, with 792 (62.8%) returned. Privacy, empathy, MDM, and personalized care scores were significantly higher after visits when physicians considered pharmacogenomic results. Importantly, personalized care scores were significantly higher after physicians used pharmacogenomic information to guide medication changes (4.0 [1.4] vs. 3.0 [1.6]; P < 0.001) compared with prescribing visits without genomic guidance. Multivariable modeling controlling for clinical factors confirmed personalized care scores were more favorable after visits with genomic-influenced prescribing (odds ratio [OR] = 3.26; 95% confidence interval [CI] = (1.31-8.14); P < 0.05). Physicians seem to individualize care when utilizing pharmacogenomic results and this decision-making augmentation is perceived positively by patients.

Vegetable organogels incorporation in cream cheese products.

Edible oleogels made from rice bran wax (RBW) or ethylcellulose (EC) organogelators in combination with vegetable oils and other non-fat ingredients were used to produce oleogel cream cheese products. Four oleogel cream cheese products, two containing RBW and two with EC, were prepared and compared to control samples including full-fat and fat-free commercial cream cheese samples. Upon compositional analysis, all the oleogel cream cheese (OCC) samples showed approximately a 25% reduction in total fat content in comparison to the full-fat commercial control. More specifically by the replacement of saturated fat with healthier unsaturated fat alternatives, an improved fatty acid profile of cream cheese products was documented. Similar compositional analysis was also performed on a cream cheese sample made with non-gelled vegetable oil. Using a single penetration test and a strain sweep test, oleogel cream cheese samples prepared with RBW displayed comparable hardness, spreadability, and stickiness values to the full-fat commercial control sample. EC OCC samples also showed comparable hardness, spreadability and stickiness values but exhibited reduced adhesiveness values compared to the full-fat control. The successful microstructural incorporation of oleogels into a cream cheese, along with similarities in fat globule size, between OCC samples and commercial controls was confirmed with Confocal Laser Scanning Microscopy. The similarity in microstructure can be accounted for the similarities in textural properties between the OCC samples and the full-fat control. These results provide a thorough characterization of the use of RBW and EC in oleogels and their potential as a healthy alternative to saturated fat in cream cheese applications.

Headspace quantification of pure and aqueous solutions of binary mixtures of key volatile organic compounds in Swiss cheeses using selected ion flow tube mass spectrometry.

RATIONALE: Twelve volatile organic compounds (VOCs) have recently been identified as key compounds in Swiss cheese with split defects. It is important to know how these VOCs interact in binary mixtures and if their behavior changes with concentration in binary mixtures. METHODS: Selected ion flow tube mass spectrometry (SIFT-MS) was used for the headspace analysis of VOCs commonly found in Swiss cheeses. Headspace (H/S) sampling and quantification checks using SIFT-MS and further linear regression analyses were carried out on twelve selected aqueous solutions of VOCs. Five binary mixtures of standard solutions of VOCs were also prepared and the H/S profile of each mixture was analyzed. RESULTS: A very good fit of linearity for the twelve VOCs (95% confidence level) confirms direct proportionality between the H/S and the aqueous concentration of the standard solutions. Henry's Law coefficients were calculated with a high degree of confidence. SIFT-MS analysis of five binary mixtures showed that the more polar compounds reduced the H/S concentration of the less polar compounds, while the addition of a less polar compound increased the H/S concentration of the more polar compound. CONCLUSIONS: In the binary experiment, it was shown that the behavior of a compound in the headspace can be significantly affected by the presence of another compound. Thus, the matrix effect plays a significant role in the behavior of molecules in a mixed solution.

Analysis of selected volatile organic compounds in split and nonsplit swiss cheese samples using selected-ion flow tube mass spectrometry (SIFT-MS).

Splits/cracks are recurring product defects that negatively affect the Swiss cheese industry. Investigations to understand the biophysicochemical aspects of these defects, and thus determine preventive measures against their occurrence, are underway. In this study, selected-ion, flow tube mass spectrometry was employed to determine the volatile organic compound (VOC) profiles present in the headspace of split compared with nonsplit cheeses. Two sampling methodologies were employed: split compared with nonsplit cheese vat pair blocks; and comparison of blind, eye, and split segments within cheese blocks. The variability in VOC profiles was examined to evaluate the potential biochemical pathway chemistry differences within and between cheese samples. VOC profile inhomogeneity was most evident in cheeses between factories. Evaluation of biochemical pathways leading to the formation of key VOCs differentiating the split from the blind and eye segments within factories indicated release of additional carbon dioxide by-product. These results suggest a factory-dependent cause of split formation that could develop from varied fermentation pathways in the blind, eye, and split areas within a cheese block. The variability of VOC profiles within and between factories exhibit varied biochemical fermentation pathways that could conceivably be traced back in the making process to identify parameters responsible for split defect.

Discrimination of Swiss cheese from 5 different factories by high impact volatile organic compound profiles determined by odor activity value using selected ion flow tube mass spectrometry and odor threshold.

Swiss cheese contains more than 200 volatile organic compounds (VOCs). Gas chromatography-mass spectrometry has been utilized for the analysis of volatile compounds in food products; however, it is not sensitive enough to measure VOCs directly in the headspace of a food at low concentrations. Selected ion flow tube mass spectrometry (SIFT-MS) provides a basis for determining the concentrations of VOCs in the head space of the sample in real time at low concentration levels of parts per billion/trillion by volume. Of the Swiss cheese VOCs, relatively few have a major impact on flavor quality. VOCs with odor activity values (OAVs) (concentration/odor threshold) greater than one are considered high-impact flavor compounds. The objective of this study was to utilize SIFT-MS concentrations in conjunction with odor threshold values to determine OAVs thereby identifying high-impact VOCs to use for differentiating Swiss cheese from five factories and identify the factory variability. Seventeen high-impact VOCs were identified for Swiss cheese based on an OAV greater than one in at least 1 of the 5 Swiss cheese factories. Of these, 2,3-butanedione was the only compound with significantly different OAVs in all factories; however, cheese from any pair of factories had multiple statistically different compounds based on OAV. Principal component analysis using soft independent modeling of class analogy statistical differentiation plots, with all of the OAVs, showed differentiation between the 5 factories. Overall, Swiss cheese from different factories was determined to have different OAV profiles utilizing SIFT-MS to determine OAVs of high impact compounds.

Effects of locust bean gum and mono- and diglyceride concentrations on particle size and melting rates of ice cream.

The objective of this study was to determine how varying concentrations of the stabilizer, locust bean gum (LBG), and different levels of the emulsifier, mono- and diglycerides (MDGs), influenced fat aggregation and melting characteristics of ice cream. Ice creams were made containing MDGs and LBG singly and in combination at concentrations ranging between 0.0% to 0.14% and 0.0% to 0.23%, respectively. Particle size analysis, conducted on both the mixes and ice cream, and melting rate testing on the ice cream were used to determine fat aggregation. No significant differences (P < 0.05) were found between particle size values for experimental ice cream mixes. However, higher concentrations of both LBG and MDG in the ice creams resulted in values that were larger than the control. This study also found an increase in the particle size values when MDG levels were held constant and LBG amounts were increased in the ice cream. Ice creams with higher concentrations of MDG and LBG together had the greatest difference in the rate of melting than the control. The melting rate decreased with increasing LBG concentrations at constant MDG levels. These results illustrated that fat aggregation may not only be affected by emulsifiers, but that stabilizers may play a role in contributing to the destabilization of fat globules.

Neural network processing of microbial fuel cell signals for the identification of chemicals present in water.

Biosensing is emerging as an important element of water quality monitoring. This research demonstrated that microbial fuel cell (MFC)-based biosensing can be integrated with artificial neural networks (ANNs) to identify specific chemicals present in water samples. The non-fermentable substrates, acetate and butyrate, induced peak areas (PA) and peak heights (PH) that were generally larger than those caused by the injection of fermentable substrates, glucose and corn starch. The ANN successfully identified peaks associated with these four chemicals under a variety of experimental conditions and for two MFCs that had different levels of sensitivity. ANNs that employ the hyperbolic tangent sigmoid transfer function performed better than those using non-continuous transfer functions. ANNs should be integrated into water quality monitoring efforts for smart biosensing.

Headspace analysis of Italian and New Zealand parmesan cheeses.

UNLABELLED: New Zealand is a leader in the global dairy industry. Milk powder is the principal export product, but there is also a prominent cheese manufacturing industry, catering more for the domestic market. The Selected Ion Flow Tube-Mass Spectrometric (SIFT-MS) technique was used to compare 4 New Zealand cheeses marketed as "parmesan" with 4 Italian Parmigiano Reggiano and Grana Padano cheeses. The cheese headspace was analyzed in real time without any sample preconcentration. Total of 38 volatile compounds in the cheese headspace were monitored with headspace concentrations varying between single digit parts per billion (ppb) to tens of parts per million (ppm). When the results were subjected to multivariate statistical analysis, a clear discrimination was found between the New Zealand "parmesan" and Italian cheeses based solely on the measured concentrations of these volatile compounds. If the volatile compounds used in the analyses were restricted to known odor-active compounds in Parmigiano Reggiano cheese, the ability to discriminate between the cheeses was maintained. The analyses also showed that it was possible to clearly differentiate between the different processing plants in individual countries. Important discriminatory volatiles in the samples tested were butanoic acid and phenylacetaldehyde for discriminating between Italian cheeses and ethyl butyrate, acetaldehyde and methylbutanals between New Zealand cheeses. We conclude that the New Zealand "parmesans" do not provide a good representation of the aroma of Italian "parmesans." PRACTICAL APPLICATION: SIFT-MS has been shown to clearly differentiate both country of origin and the manufacturer of "parmesan" cheeses made in Italy and New Zealand based on differences in volatile organic compounds. Thus this method will have benefit for use in the quality control of "parmesan" and other cheese varieties.

Rapid discrimination and characterization of vanilla bean extracts by attenuated total reflection infrared spectroscopy and selected ion flow tube mass spectrometry.

Vanilla beans have been shown to contain over 200 compounds, which can vary in concentration depending on the region where the beans are harvested. Several compounds including vanillin, p-hydroxybenzaldehyde, guaiacol, and anise alcohol have been found to be important for the aroma profile of vanilla. Our objective was to evaluate the performance of selected ion flow tube mass spectrometry (SIFT-MS) and Fourier-transform infrared (FTIR) spectroscopy for rapid discrimination and characterization of vanilla bean extracts. Vanilla extracts were obtained from different countries including Uganda, Indonesia, Papua New Guinea, Madagascar, and India. Multivariate data analysis (soft independent modeling of class analogy, SIMCA) was utilized to determine the clustering patterns between samples. Both methods provided differentiation between samples for all vanilla bean extracts. FTIR differentiated on the basis of functional groups, whereas the SIFT-MS method provided more specific information about the chemical basis of the differentiation. SIMCA's discriminating power showed that the most important compounds responsible for the differentiation between samples by SIFT-MS were vanillin, anise alcohol, 4-methylguaiacol, p-hydroxybenzaldehyde/trimethylpyrazine, p-cresol/anisole, guaiacol, isovaleric acid, and acetic acid. ATR-IR spectroscopy analysis showed that the classification of samples was related to major bands at 1523, 1573, 1516, 1292, 1774, 1670, 1608, and 1431 cm(-1) , associated with vanillin and vanillin derivatives.

Electron density-based transformation of trimethoprim during biological wastewater treatment.

This research investigated the biological transformation of trimethoprim (TMP). Partial TMP removal was observed in the presence of ammonia and toluene, and increasing the solids retention time from 20 days to 60 days improved TMP removal in both the nitrifying and heterotrophic bioreactors. Two TMP-related metabolites were identified, the first (5-(3,4,5-trimethoxybenzyl) pyrimidine-2,4-diamine, 5-hydroxyl) showing that a hydroxylation reaction took place, and the second (5-(1-carboxyl, 1-methoxy, 5-methoxy 1-,4-pentene) pyrimidine-2,4-diamine, 5-hydroxyl) showing that the trimethoxybenzyl ring was cleaved. This research is the first that we are aware of to report these two TMP-related byproducts. TMP metabolites show that initiating reactions take place where the electron density is highest, and that these initiating reactions shift the electron density of TMP, likely affecting the course of transformation.

Multicomponent cleaning verification of stainless steel surfaces for the removal of dairy residues using infrared microspectroscopy.

UNLABELLED: The application of infrared microspectroscopy (IRMS) technology, combined with multivariate analysis, was evaluated to develop sensitive and robust methods to assess cleanability of stainless steel surfaces for the removal of dairy food residues. UHT milk samples (skim, 1%, 2%, and whole) were analyzed for total nitrogen (Kjeldahl) and fat (Babcock) contents. The coupons were manually soiled with serially diluted milk samples resulting in soils ranging from 0.1 to 428.1 µg/cm(2) for protein and 0.1 to 374.17 µg/cm(2) for fat, and then autoclaved to simulate a heated equipment surface. Reflectance spectra were collected from stainless steel coupons by using IRMS, and multivariate analysis was used to develop calibration models based on cross-validated partial least squares regression (PLSR). Statistical analysis for the prediction of protein and fat showed a standard error of cross-validation (SECV) of 0.5 and 0.4 µg/cm(2) for prediction of protein and fat, respectively, and correlation coefficients (rVal) > 0.99. To improve the sensitivity, swabbing and concentration steps were used prior to IRMS analysis obtaining SECV of 0.04 and 0.01 µg/cm(2) for the prediction of protein and fat, respectively, and rVal > 0.99. The PLSR models accurately predicted the levels of protein and fat on autoclaved stainless steel coupons soiled with milk. A simple, reliable, and robust protocol based on IRMS and multivariate analysis was developed for multicomponent characterization of stainless steel surfaces that can contribute to more efficient cleaning verification with regard to contamination on surfaces of processing equipment. PRACTICAL APPLICATION: We report the application of Fourier transform infrared microspectroscopy (FTIR) for the validation of CIP cleaning efficiency that would provide a basis for better understanding of the mechanisms involved in the removal of physical soil and food residues from different types of equipment surfaces commonly utilized in the biotech, pharmaceutical, and food industries. Reliable calibration models were generated that showed the ability to predict the amounts of dairy soils on the surface of stainless steel coupons. Including a swabbing step of the coupons before infrared spectral acquisition provided improved sensitivity and reproducibility for multicomponent cleaning verification. Results from this research project would allow designing experiments to rapidly evaluate different materials and finishes, the effects of process variables, the influence of food components, and the development of reliable and robust cleaning validation protocols to ensure the safety and quality of the product.

Modified-release recombinant human TSH (MRrhTSH) augments the effect of (131)I therapy in benign multinodular goiter: results from a multicenter international, randomized, placebo-controlled study.

BACKGROUND: Recombinant human TSH (rhTSH) can be used to enhance (131)I therapy for shrinkage of multinodular goiter (MG). OBJECTIVE, DESIGN, AND SETTING: The objective of the study was to compare the efficacy and safety of 0.01 and 0.03 mg modified-release (MR) rhTSH as an adjuvant to (131)I therapy, vs. (131)I alone, in a randomized, placebo-controlled, international, multicenter study. PATIENTS AND INTERVENTION: Ninety-five patients (57.2 ± 9.6 yr old, 85% females, 83% Caucasians) with MG (median size 96.0, range 31.9-242.2 ml) were randomized to receive placebo (group A, n = 32), MRrhTSH 0.01 mg (group B, n = 30), or MRrhTSH 0.03 mg (group C, n = 33) 24 h before a calculated activity of (131)I. MAIN OUTCOME MEASURES: The primary end point was a change in thyroid volume (by computerized tomography scan, at 6 months). Secondary end points were the smallest cross-sectional area of the trachea; thyroid function tests; Thyroid Quality of Life Questionnaire; electrocardiogram; and hyperthyroid symptom scale. RESULTS: Thyroid volume decreased significantly in all groups. The reduction was comparable in groups A and B (23.1 ± 8.8 and 23.3 ± 16.5%, respectively; P = 0.95). In group C, the reduction (32.9 ± 20.7%) was more pronounced than in groups A (P = 0.03) and B. The smallest cross-sectional area of the trachea increased in all groups: 3.8 ± 2.9% in A, 4.8 ± 3.3% in B, and 10.2 ± 33.2% in C, with no significant difference among the groups. Goiter-related symptoms were effectively reduced and there were no major safety concerns. CONCLUSION: In this dose-selection study, 0.03 mg MRrhTSH was the most efficacious dose as an adjuvant to (131)I therapy of MG. It was well tolerated and significantly augmented the effect of (131)I therapy in the short term. Larger studies with long-term follow-up are warranted.

High-pressure effects on the microstructure, texture, and color of white-brined cheese.

UNLABELLED: White-brined cheeses were subjected to high-pressure processing (HPP) at 50, 100, 200, and 400 MPa at 22 °C for 5 and 15 min and ripened in brine for 60 d. The effects of pressure treatment on the chemical, textural, microstructural, and color were determined. HPP did not affect moisture, protein, and fat contents of cheeses. Similar microstructures were obtained for unpressurized cheese and pressurized cheeses at 50 and 100 MPa, whereas a denser and continuous structure was obtained for pressurized cheeses at 200 and 400 MPa. These microstructural changes exhibited a good correlation with textural changes. The 200 and 400 MPa treatments resulted in significantly softer, less springy, less gummy, and less chewy cheese. Finally, marked differences were obtained in a* and b* values at higher pressure levels for longer pressure-holding time and were also supported by ΔE* values. The cheese became more greenish and yellowish with the increase in pressure level. PRACTICAL APPLICATION: The quality of cheese is the very important to the consumers. This study documented the pressure-induced changes in selected quality attributes of semisoft and brine-salted cheese. The results can help the food processors to have knowledge of the process parameters resulting in quality changes and to identify optimal process parameters for preserving pressure-treated cheeses.

Temporal trends in primary total hip and knee arthroplasty surgery: results from a UK regional joint register, 1991-2004.

INTRODUCTION: The aim of this study was to evaluate temporal trends in the prevalence of primary total hip and knee replacements (THRs and TKRs) throughout the Trent region from 1991 to 2004. PATIENTS AND METHODS: The Trent Regional Arthroplasty Study records details of primary THR and TKR prospectively and data from the register were examined. Age and gender population data were provided by the Office for National Statistics. RESULTS: A total of 26,281 THRs and 23,606 TKRs were recorded during this period. Analysis showed that females had an increased incidence rate ratio (IRR) for both primary THR (IRR = 1.29; 95% CI 1.26-1.33; P < 0.001) and TKR (IRR = 1.17; 95% CI 1.14-1.20; P < 0.001). Patients aged 74-85 years had the largest IRR for both primary THR (IRR = 6.7; 95% CI 6.4-7.0; P < 0.001) and TKR (IRR = 15.3; 95% CI 14.4-16.3; P < 0.001). CONCLUSIONS: The prevalence of primary TKR increased significantly over time whereas THR remained steady in the Trent region between 1991 and 2004.

A new musculoskeletal curriculum: has it made a difference?

This study assessed whether undergraduate performance improved following the introduction in 2006 of a musculoskeletal teaching programme lasting for seven weeks. Different methods were used to deliver knowledge and skills in trauma and orthopaedic surgery, rheumatology and allied specialties. The programme combined four main elements: traditional firm-based teaching, weekly plenary sessions, a task-based workbook and additional specialist clinics. The block of 139 students who attended in its first year were assessed using a multiple choice question examination just before their final examinations in 2008. They showed a 6% improvement in performance over a control group of 130 students assessed in 2005 before the programme had commenced. There was no difference in performance between the students assessed in 2005 and a second group of 46 students from 2008 who did not attend the new teaching programme. Performance was improved by providing more focused musculoskeletal training using available resources, as well as increasing the length of the programme.

A promise kept.

This article is largely biographical and relates to my experiences of the past 67 years in research and teaching, both of equal importance in my life. I was fortunate to start at the beginning of the development of instrumental methods of analysis and have eagerly embraced each new methodology as it became available. This paper is dedicated to all those students and colleagues who taught me much and whose efforts are mainly responsible for what has been accomplished in our work with food science and technology. The research focused primarily on trying to find out the "why" behind the problems that food, and especially the dairy products area, encountered over the past 65 years. The teaching has tried to foster thinking and problem solving.

Rapid profiling of Swiss cheese by attenuated total reflectance (ATR) infrared spectroscopy and descriptive sensory analysis.

The acceptability of cheese depends largely on the flavor formed during ripening. The flavor profiles of cheeses are complex and region- or manufacturer-specific which have made it challenging to understand the chemistry of flavor development and its correlation with sensory properties. Infrared spectroscopy is an attractive technology for the rapid, sensitive, and high-throughput analysis of foods, providing information related to its composition and conformation of food components from the spectra. Our objectives were to establish infrared spectral profiles to discriminate Swiss cheeses produced by different manufacturers in the United States and to develop predictive models for determination of sensory attributes based on infrared spectra. Fifteen samples from 3 Swiss cheese manufacturers were received and analyzed using attenuated total reflectance infrared spectroscopy (ATR-IR). The spectra were analyzed using soft independent modeling of class analogy (SIMCA) to build a classification model. The cheeses were profiled by a trained sensory panel using descriptive sensory analysis. The relationship between the descriptive sensory scores and ATR-IR spectra was assessed using partial least square regression (PLSR) analysis. SIMCA discriminated the Swiss cheeses based on manufacturer and production region. PLSR analysis generated prediction models with correlation coefficients of validation (rVal) between 0.69 and 0.96 with standard error of cross-validation (SECV) ranging from 0.04 to 0.29. Implementation of rapid infrared analysis by the Swiss cheese industry would help to streamline quality assurance.

Application of infrared microspectroscopy and multivariate analysis for monitoring the effect of adjunct cultures during Swiss cheese ripening.

Improved cheese flavor has been attributed to the addition of adjunct cultures, which provide certain key enzymes for proteolysis and affect the dynamics of starter and nonstarter cultures. Infrared microspectroscopy provides unique fingerprint-like spectra for cheese samples and allows for rapid monitoring of cheese composition during ripening. The objective was to use infrared microspectroscopy and multivariate analysis to evaluate the effect of adjunct cultures on Swiss cheeses during ripening. Swiss cheeses, manufactured using a commercial starter culture combination and 1 of 3 adjunct Lactobacillus spp., were evaluated at d 1, 6, 30, 60, and 90 of ripening. Cheese samples (approximately 20 g) were powdered with liquid nitrogen and homogenized using water and organic solvents, and the water-soluble components were separated. A 3-microL aliquot of the extract was applied onto a reflective microscope slide, vacuum-dried, and analyzed by infrared microspectroscopy. The infrared spectra (900 to 1,800 cm(-1)) produced specific absorption profiles that allowed for discrimination among different cheese samples. Cheeses manufactured with adjunct cultures showed more uniform and consistent spectral profiles, leading to the formation of tight clusters by pattern-recognition analysis (soft independent modeling of class analogy) as compared with cheeses with no adjuncts, which exhibited more spectral variability among replicated samples. In addition, the soft independent modeling of class analogy discriminating power indicated that cheeses were differentiated predominantly based on the band at 1,122 cm(-1), which was associated with S-O vibrations. The greatest changes in the chemical profile of each cheese occurred between d 6 and 30 of warm-room ripening. The band at 1,412 cm(-1), which was associated with acidic AA, had the greatest contribution to differentiation, indicating substantial changes in levels of proteolysis during warm-room ripening in addition to propionic acid, acetic acid, and eye formation. A high-throughput infrared microspectroscopy technique was developed that can further the understanding of biochemical changes occurring during the ripening process and provide insight into the role of adjunct nonstarter lactic acid bacteria on the complex process of flavor development in cheeses.