Method of Improving Cheese Quality

A method is provided for improving the quality of cheese produced from a curd and whey mixture. The method comprises the steps of monitoring the curd and whey mixture during syneresis processing to collect color data, comparing the color data to a predetermined standard and terminating syneresis when the color meets the predetermined standard or, alternatively, analyzing the color data obtained to generate kinetic parameters that can be used to predict the end point of syneresis to improve control of curd moisture content

Online, Continuous Sensor and Method for Curd Moisture Content Control in Cheese Making

A method is provided for improving quality of cheese produced from a milk batch. A light beam from an incident light source impinges onto a surface of the milk batch, and light backscatter is optically detected during a coagulation process and correlated to an optimum cutting time for the milk coagulum. Next, light backscattered from a curd and whey mixture derived from the milk batch during a syneresis process is optically detected and correlated to an optimum syneresis endpoint. At least one of the backscattered light data, optical parameters developed from analysis of the backscattered light data, and whey fat dilution are correlated to at least one of a milk protein %, a milk fat %, a milk total solids content, a milk processing temperature, a curd moisture content, a curd moisture change over time, whey fat content, a whey fat loss, and a final curd yield

Rapid analysis of magnesium in infant formula powder using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was investigated to determine magnesium (Mg) content in infant formula powder. To predict Mg content in the range established by the Codex Alimentarius, a partial least squares regression (PLSR) model was developed using a calibration data set (n = 30) based on full cross-validation and validated using an independent validation data set (n = 21). The prediction model performance was evaluated using the regression coefficients of determination (Rcv2 = 0.94 and Rp2 = 0.85) with the root mean square errors on cross-validation and prediction (RMSECV = 60 mg kg−1 and RMSEP = 80 mg kg−1). The limit of detection (150 mg kg−1) was also calculated. In addition, LIBS successfully predicted the Mg content distributed within a pellet. This study demonstrated that LIBS is suitable as a rapid reagent-free method for the quantification of Mg in powdered infant formula and can provide spatial information with acceptable accuracy

The Application of On-line Sensors and Novel Control Technologies for Food Processing

End of Project ReportThe objective of this research was to apply on-line continuous sensors in food processing, in particular in cheese and milk powder manufacture, in order to improve process control, for example, by achieving higher quality, increased yields, reduced losses and less downgrading of product. This project focused on technologies for monitoring rheologyrelated parameters. The main conclusions were as follows: * Seven systems for monitoring curd formation in cheesemaking were evaluated in the laboratory. * Two on-line systems for monitoring curd firmness (hot-wire and NIR reflectance) have been deployed in a commercial cheese plant with promising results. * Experimental results demonstrated that NIR reflectance / transmission probes have a potential for on-line application in cheesemaking. Despite the difference in scale, the commercial sensors compared well with the cheesemaker s observation of curd firming and look promising as an objective means of predicting curd cut time in an industrial cheese plan. * A detailed knowledge of the rheological variation in cheese curd has been developed and a means of investigating factors which influence the rheology of cheese curd (e.g. effect of heat treatment or fortification of cheesemilk) has been determined. * Technologies available for monitoring concentrate viscosity changes in the production of milk powder have been assembled at pilot scale, and initial trials have been encouraging. Further evaluation of the MTL plant to assess on-line performance, ruggedness and cleanability are planned.Department of Agriculture, Food and the Marin

Modelling the biochemical and sensory changes of strawberries during storage under diverse relative humidity conditions

Many studies stress the importance of keeping strawberries at high relative humidity conditions during postharvest storage. However, the effect of deviations occurring across the supply chain on the appearance, acceptability and biochemical properties of strawberries has not been adequately explored or quantified to date using kinetic modelling applications. This study investigated the effect of relative humidity (RH)on degradation kinetics of quality and biochemical properties of ‘Strawberry Festival’, during 7 days of storage at 2 °C, using zero, first-order and Weibull models. The strawberries were stored at 40, 60, 70, 80 or 90% RH and were evaluated using subjective quality evaluation, weight loss monitoring and biochemical analysis. The shelf life was established based on current industry practices using subjective quality evaluation, namely shrivelling and colour scores. The Weibull model was found to better fit the experimental chemical analysis data compared to zero and first order kinetics models. The analysis of the rate constants quantified the significant effect of RH conditions on the weight loss and degradation rate of chemical components. Storage at low RH conditions accelerated the loss of ascorbic acid, and anthocyanins and negatively affect the in vitro antioxidant activity. The overall appearance of strawberries was modelled with zero-order kinetic model and the results revealed that lower RH conditions can limit the remaining shelf life of fresh strawberries by increasing the rate of appearance deterioration. Using RH and time as predictors in a logistic regression model, the waste occurring due to unacceptable strawberry quality, was predicted; highlighting the importance of using RH in predictive modelling when designing supply chains with the view to minimise losses.European Commission Horizon 2020USDA–NIFA Specialty Crop Research Initiative Gran

Fluorescence-based analyser as a rapid tool for determining soluble protein content in dairy ingredients and infant milk formula

Abstract: Milk protein, in particular native whey protein, is of interest to dairy manufacturers as a measure of functional and nutritional quality. However, quantification of soluble whey protein (SP) is time consuming; giving rise to the need to develop rapid, accurate, and portable at-line process analytical technology. In this study, the performance of a fluorescence-based analyser(F) (Amaltheys II, Spectralys Innovations, France) was evaluated for quantification of SPF and whey protein nitrogen index (WPNI)F in skim milk, whey protein concentrate and infant formula powders. Rehydration of powders prior to analysis was a key factor for ensuring repeatability and reproducibility. A comparison of the analyser with reference methods for SPF and WPNIF resulted in coefficient of determination (R2) > 0.993 for both SPKjeldahl method and WPNIGEA. The results show the fluorescence-based analyser to be rapid, compact, and accurate device, suited for providing reliable support to dairy ingredient and infant formula manufacturers. Industrial relevance: The fluorescence based analysis investigated in this article is suitable for application in the dairy industry where it can be used as a rapid, at-line PAT tool for both liquid and powder samples. The technology has the potential to replace well-established methods for measurement of soluble protein. The main benefit to industry is the ability to respond more rapidly to variations in soluble protein without compromising on the accuracy associated with more time consuming methods

On-line Sensor Control for Milk Powder and Cheese Manufacture.

End of Project ReportThis project investigated the use of on-line sensors of rheological characteristics which can be measured during the manufacture of milk powder and cheese. The objective is to use on-line measurements to fine tune each process, so as to compensate for the variability of milk.Department of Agriculture, Food and the Marin

Assessment of physico-chemical traits related to eating quality of young dairy bull beef at different ageing times using Raman spectroscopy and chemometrics

Raman spectroscopy and chemometrics were investigated for the prediction of eating quality related physico-chemical traits of Holstein-Friesian bull beef. Raman spectra were collected on the 3rd, 7th and 14th days post-mortem. A frequency range of 1300–2800 cm− 1 was used for partial least squares (PLS) modelling. PLS regression (PLSR) models for the prediction of WBSF and cook loss achieved an R2CV of 0.75 with RMSECV of 6.82 N and an R2CV of 0.77 with RMSECV of 0.97%w/w respectively. For the prediction of intramuscular fat, moisture and crude protein content, R2CV values were 0.85, 0.91 and 0.70 with RMSECV of 0.52%w/w, 0.39%w/w and 0.38%w/w respectively. An R2CV of 0.79 was achieved for the prediction of both total collagen and hydroxyproline content, while for collagen solubility the R2CV was 0.88. All samples (100%) from 15- and 19-month old bulls were correctly classified using PLS discriminant analysis (PLS-DA), while 86.7% of samples from different muscles (longissimus thoracis, semitendinosus and gluteus medius) were correctly classified. In general, PLSR models using Raman spectra on the 3rd day post-mortem had better prediction performance than those on the 7th and 14th days. Raman spectroscopy and chemometrics have potential to assess several beef physical and chemical quality traits

Arac-type regulator rbf controls the staphylococcus epidermidis biofilm phenotype by negatively regulating theicaadbcrepressor sarr

Regulation of icaADBC-encoded polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosasmine (PNAG) production in staphylococci plays an important role in biofilm-associated medical-device-related infections. Here, we report that the AraC-type transcriptional regulator Rbf activates icaADBC operon transcription and PIA production in Staphylococcus epidermidis. Purified recombinant Rbf did not bind to the ica operon promoter region in electrophoretic mobility shift assays (EMSAs), indicating that Rbf regulates ica transcription indirectly. To identify the putative transcription factor(s) involved in Rbf-mediated icaADBC regulation, the ability of recombinant Rbf to interact with the promoter sequences of known icaADBC regulators was investigated. Recombinant Rbf bound to the sarR promoter and not the sarX, sarA, sarZ, spx, and srrA promoters. Reverse transcription (RT)-PCR demonstrated that Rbf acts as a repressor of sarR transcription. PIA expression and biofilm production were restored to wild-type levels in an rbf sarR double mutant grown in brain heart infusion (BHI) medium supplemented with NaCl, which is known to activate the ica locus, but not in BHI medium alone. RT-PCR further demonstrated that although Rbf does not bind the sarX promoter, it nevertheless exerted a negative effect on sarX expression. Apparently, direct downregulation of the SarR repressor by Rbf has a dominant effect over indirect repression of the SarX activator by Rbf in the control of S. epidermidis PIA production and biofilm formation. IMPORTANCE The importance of Staphylococcus epidermidis as an opportunistic pathogen in hospital patients with implanted medical devices derives largely from its capacity to form biofilm. Expression of the icaADBC-encoded extracellular polysaccharide is the pre-dominant biofilm mechanism in S. epidermidis clinical isolates and is tightly regulated. Here, we report that the transcriptional regulator Rbf promotes icaADBC expression by negatively regulating expression of sarR, which encodes an ica operon repressor. Furthermore, Rbf indirectly represses the ica operon activator, SarX. The data reveal complicated interplay between Rbf and two Sar family proteins in fine-tuning regulation of the biofilm phenotype and indicate that in the hierarchy of biofilm regulators, IcaR is dominant over the Rbf-SarR-SarX axis