Impact of model fat emulsions on sensory perception using repeated spoon to spoon ingestion.

Eating is a dynamic behaviour, in which food interacts with the mechanical and physiological environment of the mouth. This dynamic interaction changes the oral surfaces leaving particles of food and building up a film on the oral surfaces, which may impact on the temporal perception during the eating experience. The effect of repeated spoon to spoon ingestion of oil in water emulsion products (2%-50% w/w oil) was evaluated using descriptive in-mouth and after swallowing sensory attributes. Descriptive sensory analysis indicated that fatty mouthfeel and afterfeel perception (measured post swallowing) increased with the number of spoonfuls for emulsions containing 50% fat. This effect is likely due to the build-up of oil droplet layers deposited on the mouth surfaces. There was an enhancement of fatty afterfeel intensity for 50% fat emulsions containing the more lipophilic aroma ethylhexanoate compared to ethyl butanoate, indicating a cross-modal interaction. No increase in these attributes from spoon to spoon was observed for the low oil emulsions; since most of the oil in the emulsion was swallowed and very little oil was likely to be left in the mouth. Sweetness perception increased as fat level increased in the emulsion due to an increase in the effective concentration of sugar in the aqueous phase. However, the sweetness perceived did not change from spoon to spoon, suggesting that any oil-droplets deposited on the oral surfaces did not form a complete barrier, restricting access of the sucrose to the taste buds. This study highlights the importance of measuring the dynamic nature of eating and demonstrated change in sensory perception occurring with repeated ingestion of model emulsions, which was likely due to a change in mouth environment.

ProLuCID: An improved SEQUEST-like algorithm with enhanced sensitivity and specificity.

ProLuCID, a new algorithm for peptide identification using tandem mass spectrometry and protein sequence databases has been developed. This algorithm uses a three tier scoring scheme. First, a binomial probability is used as a preliminary scoring scheme to select candidate peptides. The binomial probability scores generated by ProLuCID minimize molecular weight bias and are independent of database size. A modified cross-correlation score is calculated for each candidate peptide identified by the binomial probability. This cross-correlation scoring function models the isotopic distributions of fragment ions of candidate peptides which ultimately results in higher sensitivity and specificity than that obtained with the SEQUEST XCorr. Finally, ProLuCID uses the distribution of XCorr values for all of the selected candidate peptides to compute a Z score for the peptide hit with the highest XCorr. The ProLuCID Z score combines the discriminative power of XCorr and DeltaCN, the standard parameters for assessing the quality of the peptide identification using SEQUEST, and displays significant improvement in specificity over ProLuCID XCorr alone. ProLuCID is also able to take advantage of high resolution MS/MS spectra leading to further improvements in specificity when compared to low resolution tandem MS data. A comparison of filtered data searched with SEQUEST and ProLuCID using the same false discovery rate as estimated by a target-decoy database strategy, shows that ProLuCID was able to identify as many as 25% more proteins than SEQUEST. ProLuCID is implemented in Java and can be easily installed on a single computer or a computer cluster. This article is part of a Special Issue entitled: Computational Proteomics.

Current guidelines for nut consumption are achievable and sustainable: a hazelnut intervention.

Nuts are known for their hypocholesterolaemic properties; however, to achieve optimal health benefits, nuts must be consumed regularly and in sufficient quantity. It is therefore important to assess the acceptability of regular consumption of nuts. The present study examined the long-term effects of hazelnut consumption in three different forms on 'desire to consume' and 'overall liking'. A total of forty-eight participants took part in this randomised cross-over study with three dietary phases of 4 weeks: 30 g/d of whole, sliced and ground hazelnuts. 'Overall liking' was measured in a three-stage design: a pre- and post-exposure tasting session and daily evaluation over the exposure period. 'Desire to consume' hazelnuts was measured during the exposure period only. Ratings were measured on a 150 mm visual analogue scale. Mean ratings of 'desire to consume' were 92 (SD 35) mm for ground, 108 (SD 33) mm for sliced and 116 (SD 30) mm for whole hazelnuts. For 'overall liking', the mean ratings were 101 (SD 29) mm for ground, 110 (SD 32) mm for sliced and 118 (SD 30) mm for whole hazelnuts. Ground hazelnuts had significantly lower ratings than both sliced (P ≤ 0·034) and whole hazelnuts (P < 0·001), with no difference in ratings between sliced and whole hazelnuts (P ≥ 0·125). For each form of nut, ratings of 'overall liking' and 'desire to consume' were stable over the exposure period, indicating that not only did the participants like the nuts, but also they wished to continue eating them. Therefore, the guideline to consume nuts on a regular basis appears to be a sustainable behaviour to reduce CVD.

Effects of different forms of hazelnuts on blood lipids and α-tocopherol concentrations in mildly hypercholesterolemic individuals.

BACKGROUND/OBJECTIVES: Diets high in nuts reduce cholesterol, probably due to their favorable lipid profile and other bioactive substances. However, the physical form of the nut may be important as the cell wall of intact nuts may limit the hypocholesterolemic effect of nuts by reducing lipid bioavailability. Therefore, we investigated the effects on blood lipids of incorporating three different forms of hazelnuts (ground, sliced and whole) into the usual diet. SUBJECTS/METHODS: In a randomized crossover study with three phases, 48 mildly hypercholesterolemic participants were asked to consume 30 g of ground, sliced or whole hazelnuts for 4 weeks. Body weight, plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triacylglycerol (TAG), apolipoprotein (apo) A1, apo B100 and α-tocopherol were measured at baseline and at the end of each dietary phase. RESULTS: There were no significant differences in any outcome variable between the different forms of nuts (all P ≥ 0.159). However, compared with baseline, mean values at the end of each hazelnut intervention were significantly higher for HDL-C (P = 0.023) and α-tocopherol (P = 0.005), and significantly lower for TC (P < 0.001), LDL-C (P < 0.001), TC:HDL-C ratio (P <0 .001), apo B100 (P = 0.002) and apo B100:apo A1 ratio (P < 0.001), with no significant difference in body weight (P = 0.813). CONCLUSIONS: The ingestion of three different forms of hazelnuts equally improved the lipoprotein profile and α-tocopherol concentrations in mildly hypercholesterolemic individuals. Hazelnuts can therefore be incorporated into the usual diet as a means of reducing cardiovascular disease risk.

Application of mid-infrared spectroscopy to the prediction of maturity and sensory texture attributes of cheddar cheese.

The objective of this study was to determine the potential of mid-infrared spectroscopy in conjunction with partial least squares (PLS) regression to predict various quality parameters in cheddar cheese. Cheddar cheeses (n= 24) were manufactured and stored at 8 degrees C for 12 mo. Mid-infrared spectra (640 to 4000/cm) were recorded after 4, 6, 9, and 12 mo storage. At 4, 6, and 9 mo, the water-soluble nitrogen (WSN) content of the samples was determined and the samples were also evaluated for 11 sensory texture attributes using descriptive sensory analysis. The mid-infrared spectra were subjected to a number of pretreatments, and predictive models were developed for all parameters. Age was predicted using scatter-corrected, 1st derivative spectra with a root mean square error of cross-validation (RMSECV) of 1 mo, while WSN was predicted using 1st derivative spectra (RMSECV = 2.6%). The sensory texture attributes most successfully predicted were rubbery, crumbly, chewy, and massforming. These attributes were modeled using 2nd derivative spectra and had corresponding RMSECV values in the range of 2.5 to 4.2 on a scale of 0 to 100. It was concluded that mid-infrared spectroscopy has the potential to predict age, WSN, and several sensory texture attributes of cheddar cheese.

Evaluating mid-infrared spectroscopy as a new technique for predicting sensory texture attributes of processed cheese.

The objective of this study was to investigate the potential application of mid-infrared spectroscopy for determination of selected sensory attributes in a range of experimentally manufactured processed cheese samples. This study also evaluates mid-infrared spectroscopy against other recently proposed techniques for predicting sensory texture attributes. Processed cheeses (n = 32) of varying compositions were manufactured on a pilot scale. After 2 and 4 wk of storage at 4 degrees C, mid-infrared spectra (640 to 4,000 cm(-1)) were recorded and samples were scored on a scale of 0 to 100 for 9 attributes using descriptive sensory analysis. Models were developed by partial least squares regression using raw and pretreated spectra. The mouth-coating and mass-forming models were improved by using a reduced spectral range (930 to 1,767 cm(-1)). The remaining attributes were most successfully modeled using a combined range (930 to 1,767 cm(-1) and 2,839 to 4,000 cm(-1)). The root mean square errors of cross-validation for the models were 7.4 (firmness; range 65.3), 4.6 (rubbery; range 41.7), 7.1 (creamy; range 60.9), 5.1 (chewy; range 43.3), 5.2 (mouth-coating; range 37.4), 5.3 (fragmentable; range 51.0), 7.4 (melting; range 69.3), and 3.1 (mass-forming; range 23.6). These models had a good practical utility. Model accuracy ranged from approximate quantitative predictions to excellent predictions (range error ratio = 9.6). In general, the models compared favorably with previously reported instrumental texture models and near-infrared models, although the creamy, chewy, and melting models were slightly weaker than the previously reported near-infrared models. We concluded that mid-infrared spectroscopy could be successfully used for the nondestructive and objective assessment of processed cheese sensory quality.

Production of ingredient-type cheddar cheese with accelerated flavor development by addition of enzyme-modified cheese powder.

Fast-ripened Cheddar cheeses for ingredient purposes were produced by addition of a dried enzyme-modified cheese (EMC; 0.25 and 1 g/100 g of milled curd) at the salting stage during a standard Cheddar cheese-making procedure. Populations of starter and nonstarter lactic acid bacteria (NSLAB), levels of proteolysis and lipolysis, volatile analysis, and flavor development (by quantitative descriptive sensory analysis) were monitored over a 6-mo ripening period. Levels of free AA and free fatty acids were elevated in the experimental cheeses on d 1 because of inclusion of the EMC. Counts of NSLAB were also elevated in the experimental cheeses compared with the control cheese from the start of ripening. Levels of free AA were slightly elevated in the experimental cheeses at 1, 2, and 4 mo, but significantly greater accumulations were detected by 6 mo of ripening, with His, Leu, and glutamate reflecting the greatest increases. Levels of long-chain free fatty acids increased up to 2 mo, indicating an initial stimulation of lipolysis, but had decreased by 6 mo, indicating greater catabolism, probably caused by NSLAB and increased starter lysis. Principal component analysis of the volatile compounds showed few differences in the aroma profiles among the cheeses up to 4 mo of ripening, but a large separation of the cheeses supplemented with EMC relative to the control was observed by 6 mo. Sensory analysis of the cheeses with added EMC showed an acceleration of 2 mo in flavor development compared with the control cheese with the addition of 1 g/100 g of EMC developing a flavor profile at 4 mo similar to the control cheese at 6 mo of ripening. However, atypical Cheddar flavors developed on prolonged storage. This study shows the potential of adding EMC during Cheddar production to produce a fast-ripened ingredient-type Cheddar cheese.

Exposure, health information and flavour-masking strategies for improving the sensory quality of probiotic juice.

Probiotics are live microbial food supplements, which have been shown to exert numerous health benefits. Research has identified that probiotics cause perceptible off-flavours that often contribute to consumer dissatisfaction. This research consisted of three objectives. Firstly, to confirm whether probiotics have a significant effect on the sensory quality and the consumer acceptance of juices. Secondly, to evaluate whether the addition of tropical juices masks probiotic off-flavours, thereby increasing consumer liking. Thirdly, to determine whether non-sensory factors (i.e., repeated exposure, and health information) have an impact on consumer liking. Three orange juice products were manufactured for analysis; Control juice, juice containing probiotics, and juice containing probiotics and tropical fruit juices (10% v/v). Descriptive sensory analysis using a trained panel (n=8) determined that probiotic juices possessed unique 'medicinal' characteristics. Using labelled affective magnitude scales, consumers (n=116) evaluated their 'overall liking' of the three juices in a randomised order in the laboratory. Once assigned into one of three balanced exposure groups, each consumer took home seven, 100mL bottles of one of the juices, and consumed one bottle each day for 7 days. After each in-home consumption, consumers evaluated their 'overall liking' to familiarize themselves with the juice. Furthermore, half of the consumers were provided with information about the presence and the health benefits of probiotics, while the other half of consumers received no information. After 7 days of in-home usage, consumers returned to the laboratory for post-exposure sensory testing, where they re-evaluated their 'overall liking' of the three juices in a randomised order. Results showed that tropical juices were effective in masking the off-flavours associated with probiotic ingredients, and that consumer liking for the probiotic juice containing tropical juice flavours was maintained over the 7-day exposure period. Exposure and information had significant effects on the 'overall liking' of juices containing probiotic cultures. A significant interaction between exposure and information was observed. Therefore, exposure, health information and flavour-masking techniques can have a positive effect on the hedonic qualities of probiotic juices.

Composition, sensory and shelf life stability analyses of Longissimus dorsi muscle from steers reared under organic and conventional production systems.

In recent years the demand for organically grown food has increased. In this study, organic (O, n=6) and conventionally (C, n=6) reared steers aged between 18 and 24 months were slaughtered during the month of September 2002. Four days post-slaughter, the Longissimus dorsi (LD) muscle was excised from the left side of each carcass. All muscles were vacuum packed and aged in a chill for a further seven days. Steaks were cut from each sample, and from these, lean meat was removed, blended and compositional analysis was carried out. O samples were significantly higher (P>0.05) in fat content and therefore were significantly (P>0.05) lower in moisture content than C samples. No significant differences were observed between C and O samples for protein, ash, ß-carotene, α-tocopherol or retinol. There was also no significant difference in fatty acid content between C and O samples. Colour stability and fat oxidative stability of samples were also measured, while stored under retail conditions. Samples were packed using both modified atmosphere packaging (MAP) and by overwrapping with cling film. MAP C samples had the best colour stability while overwrapped C samples had the best lipid stability. Therefore, colour and lipid stability of beef samples were influenced by sample composition and packaging format used, which resulted in C samples outperforming O samples with respect to shelf life stability.

Influence of starter culture on flavor and headspace volatile profiles of fermented whey and whey produced from fermented milk.

Rennet whey and skim milk were compared as media for fermentation by commercial cheese, yogurt, and probiotic starter cultures. Effect of culture, medium, and their interaction on flavor was assessed and compared by sensory descriptive analysis and headspace volatile analysis by proton transfer reaction-mass spectrometry. In general, the aroma of fermented whey was similar to that of whey separated from fermented milk, indicating a favorable possibility of substituting milk with whey in the manufacture of fermented milk-like beverages. Starter culture significantly affected most sensory characteristics of the products. Key volatile compounds for the characteristic flavor of yogurt, such as acetaldehyde and diacetyl, were not significantly affected by medium when fermented with the yogurt culture, and reached similar levels in both systems. Volatile analysis results were consistent with the results of the sensory evaluation, indicating the high reliability of proton transfer reaction-mass spectrometry in detecting important volatile compounds for aroma. Integration of this sensory and chemical information allows a better understanding of how flavor and related compounds are affected by ingredients or processing, which may be useful for the development of value-added whey products.

Sensory characteristics and related volatile flavor compound profiles of different types of whey.

To characterize the flavor of liquid whey, 11 samples of whey representing a wide range of types were sourced from cheese and casein-making procedures, either industrial or from pilot-plant facilities. Whey samples were assessed for flavor by descriptive sensory evaluation and analyzed for headspace volatile composition by proton transfer reaction-mass spectrometry (PTR-MS). The sensory data clearly distinguished between the samples in relation to the processes of manufacture; that is, significant differences were apparent between cheese, rennet, and acid wheys. For Mozzarella and Quarg wheys, in which fermentation progressed to low pH values, the starter cultures used for cheese making had a significant influence on flavor. In comparison, Cheddar and Gouda wheys were described by milk-like flavors, and rennet casein wheys were described by "sweet" (oat-like and "sweet") and thermally induced flavors. The volatile compound data obtained by PTR-MS differentiated the samples as distinctive and reproducible "chemical fingerprints". On applying partial least squares regression to determine relationships between sensory and volatile composition data, sensory characteristics such as "rancid" and cheese-like odors and "caramelized milk," yogurt-like, "sweet," and oat-like flavors were found to be related to the presence and absence of specific volatile compounds.

Interactions between texture and trigeminal stimulus in a liquid food system: effects on elderly consumers preferences.

Changes to the chemical senses of taste and smell that accompany ageing are widely believed to influence food preferences and consumption in the elderly. The possibility that interactions between the residual senses of texture and trigeminal perception can compensate for specific losses was explored using a complex liquid food system, soup. A consumer panel of twenty-four young people (20-35, mean age 27.7 +/- 3.95 years) and twenty-four elderly people (>65 years, mean age 73.6 +/- 5.78 years) were used for preference tests. Eight soups were prepared using a standardised recipe, with four variations in texture and two levels of trigeminal stimulus. The consumer panel preferences were measured using a nine point hedonic scale. The hedonic data was corrected for a scaling effect, and principle components analysis was completed on the normalised data of the two age cohorts. The preference decision of both age groups was in the direction of the lower level of trigeminal stimulation. Overall the older panel was less discriminating than the younger panel. However the older panel made an attempt to grade the different textures while the younger panel seemed to ignore the textural attribute in their preference decision. The older panel's preference decreased as the thickness of the soups increased across trigeminal levels. These results suggest that perhaps a judicious selection of a certain texture or mouthfeel combined with a preferred level of trigeminal irritation could boost elderly food enjoyment. Finally, a postal questionnaire was circulated to gain an insight in to the consumer's background and thus partially explain the motivation for their preferences.

Interactions between artificial saliva and 20 aroma compounds in water and oil model systems.

The interactions between saliva components and 20 aroma compounds in water and oil model systems were systematically evaluated as a function of saliva composition and saliva/model system ratio. Air/liquid partition coefficients of dimethyl sulfide, 1-propanol, diacetyl, 2-butanone, ethyl acetate, 1-butanol, 2-pentanol, propyl acetate, 3-methyl-1-butanol, ethyl butyrate, hexanal, butyl acetate, 1-hexanol, 2-heptanone, heptanal, alpha-pinene, 2-octanone, octanal, 2-nonanol, and 2-decanone were determined by static headspace gas chromatography. Chain length of compounds within the homologous series determined the extent of interactions with the model system or saliva. Salts in the artificial saliva hardly interacted with aroma compounds. On the other hand, saliva proteins lowered retention of highly volatile compounds and increased retention of less volatile, hydrophobic compounds. Significant differences in volatility of compounds when artificial saliva or water was added indicated that saliva could not be sufficiently replaced by water. The model system/saliva ratio influenced air/liquid partitioning of the aroma compounds significantly for both model systems. Although saliva composition affected volatility of the aroma compounds, the saliva/model system ratio was of much greater influence.

HealthSense: how changes in sensory physiology, sensory psychology and sociocognitive factors influence food choice.

HealthSense is a multi-centre shared cost research project in sensory and consumer sciences. This project was initiated in response to changing population demographics, which predict a significant increase in the older age group. The primary objective of HealthSense is to determine accurately the effects of ageing on the perceptual abilities of the sensory systems, and ultimately how age-related change determines sensory preferences and food choice. The project is carried out by 24 participating institutes located in 10 different European countries. The project is funded by the European Commission Quality of Life Fifth Framework Programme (QLKI-CT-1999-00010).

Genotyping by ligation assays.

This unit describes two methods of genotyping DNA sequences containing known nucleotide variations. The first protocol describes a colorimetric method for genotyping DNA samples amplified by the polymerase chain reaction (PCR) using an oligonucleotide ligation assay (OLA). The second protocol describes the ligase chain reaction (LCR), a method for simultaneously amplifying and genotyping genomic DNA samples. A Support Protocol describes the preparation of modified biotin- and digoxigenin-labeled oligonucleotide primers.

Testing the hypothesis of a recombinant origin of human immunodeficiency virus type 1 subtype E.

The human immunodeficiency virus type 1 (HIV-1) epidemic in Southeast Asia has been largely due to the emergence of clade E (HIV-1E). It has been suggested that HIV-1E is derived from a recombinant lineage of subtype A (HIV-1A) and subtype E, with multiple breakpoints along the E genome. We obtained complete genome sequences of clade E viruses from Thailand (93TH057 and 93TH065) and from the Central African Republic (90CF11697 and 90CF4071), increasing the total number of HIV-1E complete genome sequences available to seven. Phylogenetic analysis of complete genomes showed that subtypes A and E are themselves monophyletic, although together they also form a larger monophyletic group. The apparent phylogenetic incongruence at different regions of the genome that was previously taken as evidence of recombination is shown to be not statistically significant. Furthermore, simulations indicate that bootscanning and pairwise distance results, previously used as evidence for recombination, can be misleading, particularly when there are differences in substitution or evolutionary rates across the genomes of different subtypes. Taken jointly, our analyses suggest that there is inadequate support for the hypothesis that subtype E variants are derived from a recombinant lineage. In contrast, many other HIV strains claimed to have a recombinant origin, including viruses for which only a single parental strain was employed for analysis, do indeed satisfy the statistical criteria we propose. Thus, while intersubtype recombinant HIV strains are indeed circulating, the criteria for assigning a recombinant origin to viral structures should include statistical testing of alternative hypotheses to avoid inappropriate assignments that would obscure the true evolutionary properties of these viruses.

What do doctors record in the medical notes following discussion with the parents of sick premature infants?

UNLABELLED: In a retrospective review of medical notes we determined: (1) how often doctors record discussions with the parents of very low birth weight (VLBW) infants during the neonatal period; (2) what details of any discussion they actually record and; (3) if they are more likely to record discussion with the parents of sicker infants. A random sample (30%) of all VLBW infants admitted between 1989 and 1993 to a regional NICU was reviewed, n = 87. No discussion was documented in 47 cases, one of whom died, 24 had a single episode of discussion recorded and 16 had two or more episodes recorded. Specific discussion about prognosis was only recorded in the notes of 27 babies. Discussion was more likely to be documented in sicker infants as measured by CRIB (clinical risk index for babies) score, t = -3.9, P < 0.001. CONCLUSION: A record of discussion between medical staff and parents is found in the medical notes of less than half of all VLBW infants. These findings may have practical, ethical and legal implications.

Evolution of a simian immunodeficiency virus pathogen.

Analysis of disease induction by simian immunodeficiency viruses (SIV) in macaques was initially hampered by a lack of molecularly defined pathogenic strains. The first molecularly cloned SIV strains inoculated into macaques, SIVmacBK28 and SIVmacBK44 (hereafter designated BK28 and BK44, respectively), were cases in point, since they failed to induce disease within 1 year postinoculation in any inoculated animal. Here we report the natural history of infection with BK28 and BK44 in inoculated rhesus macaques and efforts to increase the pathogenicity of BK28 through genetic manipulation and in vivo passage. BK44 infection resulted in no disease in four animals infected for more than 7 years, whereas BK28 induced disease in less than half of animals monitored for up to 7 years. Elongation of the BK28 transmembrane protein (TM) coding sequence truncated by prior passage in human cells marginally increased pathogenicity, with two of four animals dying in the third year and one dying in the seventh year of infection. Modification of the BK28 long terminal repeat to include four consensus nuclear factor SP1 and two consensus NF-kappaB binding sites enhanced early virus replication without augmenting pathogenicity. In contrast, in vivo passage of BK28 from the first animal to die from immunodeficiency disease (1.5 years after infection) resulted in a consistently pathogenic strain and a 50% survival time of about 1.3 years, thus corresponding to one of the most pathogenic SIV strains identified to date. To determine whether the diverse viral quasispecies that evolved during in vivo passage was required for pathogenicity or whether a more virulent virus variant had evolved, we generated a molecular clone composed of the 3' half of the viral genome derived from the in vivo-passaged virus (H824) fused with the 5' half of the BK28 genome. Kinetics of disease induction with this cloned virus (BK28/H824) were similar to those with the in vivo-passaged virus, with four of five animals surviving less than 1.7 years. Thus, evolution of variants with enhanced pathogenicity can account for the increased pathogenicity of this SIV strain. The genetic changes responsible for this virulent transformation included at most 59 point mutations and 3 length-change mutations. The critical mutations were likely to have been multiple and dispersed, including elongation of the TM and Nef coding sequences; changes in RNA splice donor and acceptor sites, TATA box sites, and Sp1 sites; multiple changes in the V2 region of SU, including a consensus neutralization epitope; and five new N-linked glycosylation sites in SU.

Comparison of a limited computerized diagnostic system (ResCare Autoset) with polysomnography in the diagnosis of obstructive sleep apnoea syndrome.

The increasing numbers of patients referred for evaluation of suspected obstructive sleep apnoea (OSA) places a growing burden on available sleep laboratory resources. A number of limited diagnostic systems have been developed in an effort to cope with this clinical problem. In this study, the diagnostic capabilities of one limited diagnostic system (ResCare Autoset) were compared with full polysomnography (PSG), using the Oxford SAC computerized system. Thirty six patients with suspected OSA had simultaneous studies performed both with the Autoset and Oxford PSG systems. The apnoea plus hypopnoea index (AHI) (events x h(-1)) scored by the Autoset system was compared with the AHI scored from the PSG raw tracings by an experienced sleep technician. There were highly significant correlations between the Autoset AHI and the AHI scored by the manual PSG scoring method (r=0.92; p<0.001). The positive predictive value for diagnosis of OSA for the Autoset was 86% when compared with manual PSG scoring, based on an AHI threshold for OSA of 15 events x h(-1). However, the agreement between Autoset and PSG was poor in severe cases of OSA, although not sufficiently so as to result in mistaken diagnosis in any of these cases. We conclude that the Autoset system is a sensitive and easy to use system, which facilitates screening for obstructive sleep apnoea with a reasonable degree of accuracy.