GB2249388A - Process for food analysis - Google Patents

Abstract

In a process for the analysis of discrete food samples (3) presented to an analysis instrument (2), bar codes on the samples are read by a bar code reader (5) to ensure traceability of all samples. A control unit (10) captures analysis data from the instrument (2) and determines if the analysis data is from an active sample such as that from a milk supplier or a standard sample used for calibration of the instrument (2). If the sample is a standard sample, the control unit (10) outputs on a trace recorder (14) and a VDU (15) calibration deviations so that calibration of the instrument (2) may be monitored on an on-going basis during analysis of a batch of samples (3). If a calibration deviation is excessive the control unit (10) switches off the instrument (2) to avoid the need for re-work and the risk of wrong analysis data being generated. Further, the control unit (10) compares the analysis data of active samples with historical data such as that for previous milk supplied by a particular supplier. A message is displayed at the VDU (15) if the difference is outside of a tolerance range. <IMAGE>

Description

"A Process for Food Analysis" The invention relates to a process for the analysis of food samples.

The analysis of food samples is a particularly important process, particularly where the samples are taken from food to be used for further processing. If information regarding composition or other analysis data from the food samples is delivered late or is inaccurate, processing of the food may be carried out in the wrong manner and sometimes whole batches of food are lost. Heretofore, the analysis of food samples has been carried out by collection of data from analysis instruments on tally rolls, in which case the data is manually logged into books or into a computer, or is read by a floppy disc for later reading into a computer. The analysis operation must often be repeated, for example, where it is found that the analysis instruments deviated from outer calibration limits during operation.This is time-consuming and sometimes inaccurate, and may result in delays in delivery of batches of raw materials for processing.

The present invention is directed towards providing an improved process for analysis of food samples to overcome at least some of these problems.

According to the invention there is provided a process carried out by a food analysis apparatus in analysis of a set of discrete food samples, the apparatus comprising an analysis instrument, a control unit for the instrument, storage means, a read/write memory circuit, a user input interface and a user output interface, the process comprising the steps of:: the control unit directing storage in the storage means of historical analysis data for active samples of a food, said historical analysis data being the data obtained on analysis of similar active samples on previous occasions; the control unit storing identification codes for standard samples of food; the control unit directing storage in the read/write memory circuit of reference data obtained from separate analysis of the standard samples; the control unit directing reading of an identification code of a sample presented to the instrument and capturing the identification code for storage in the read/write memory circuit; the control unit directing operation of the instrument for analysis of the sample and subsequently capturing analysis data of the sample for storage in the read/write memory circuit; the control unit comparing the captured identification code with the stored standard sample identification codes to determine if the sample is an active or a standard sample; if the sample is a standard sample, the control unit comparing the analysis data with the reference data to determine a calibration deviation; the control unit directing output of the calibration deviation at the user output interface; if the sample is an active sample, the control unit comparing the analysis data with the historical data to obtain an active sample difference; the control unit directing output of the active sample difference at the user output interface.

Ideally, the process comprises the additional step of the control unit directing calibration of the instrument, said process step involving the sub-steps of: the control unit directing storage in the storage means of reference data for standard samples; the control unit directing operation of the instrument for analysis of the standard samples; the control unit capturing analysis data of the standard samples; the control unit comparing the analysis data with the reference data to obtain a calibration deviation; the control unit directing output at the user output interface of the calibration deviation; the user input interface receiving an indication as to acceptability of the calibration deviation; and the control unit repeatedly directing output at the user output interface of a message directing re calibration of the instrument until receipt at the user input interface of an indication of acceptability of the calibration deviation.

In one embodiment, the process comprises the further steps of: the control unit directing storage in the storage means of a tolerance range for the difference between the analysis data and the historical data; and the control unit directing output of the difference at the user output interface.

Preferably, the process comprises the step of switching off the instrument if the calibration deviation exceeds a preset minimum calibration difference.

In a further embodiment, the process comprises the further steps of the control unit directing storage in the storage means of all data written to the read/write memory circuit during operation on the instrument; and merging said data with pre-set report lay outs and generating reports at the user output interface.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, given by way of example only with reference to the accompanying drawings in which: Fig. 1 is a schematic representation of an apparatus for analysis of discrete food samples; Figs. 2 and 3 are flow diagrams illustrating operation of the apparatus; and Figs. 4a to 4c are representations of graphical outputs of the apparatus.

Referring to the drawings, and initially to Fig. 1 there is illustrated an apparatus 1 for the on-going analysis of discrete food samples. The apparatus 1 comprises an analysis instrument, namely, an infra-red scanner 2 for determination of constituents of milk samples. In this embodiment the milk samples are in bottles 3 on a conveyor belt 4. The apparatus 1 includes a bar code reader 5 for reading of bar codes from labels on the bottles 3. The scanner 2 is connected to a control unit 10 connected to a fixed disc drive 11 and to a read/write memory circuit 12. A user input interface, namely, a keyboard 13 is connected to the control unit 10 and user output interfaces, namely, a trace recorder 14, and a VDU 15 are also connected to the control unit 10.

Referring to Figs. 2 to 4, operation of the apparatus 1 is illustrated. In steps 20 and 21 of Fig. 2, the control unit 10 directs storage in the fixed disc 11 of historical analysis data for a particular milk supplier and of tolerance limits for this data. In this embodiment, the analysis data comprises the constituent levels of butterfat, protein, and lactose in milk samples. Thus, the historical analysis data would be a mean for the constituent levels of milk from a particular supplier and tolerance limits would be limits outside of which the result would be considered abnormal and void for the purpose of paying the supplier, and/or additional analysis is required, and/or the type of food product which could be made from the supplied milk would change.The historical analysis data and sample tolerance limits are stored in the fixed disc 11 for permanent storage because they are used on an on-going, day-by-day basis.

Before a particular analysis process is initiated, the scanner 2 is calibrated in step 22. The process steps involved in calibration are illustrated in Fig. 3. Initially, in step 22a a number of samples, hereinafter, referred to as standard samples are analysed manually using a technique known as the "Gerber" technique. This data is manually inputted at the keyboard 13 and the control unit 10 directs storage of the data as reference data in the read/write memory circuit 12.

In step 22b, the control unit 10 directs the scanner 2 to analyse the standard samples for which reference data has been received. The control unit 10 automatically captures the analysis data in step 22c and stores it in the read/write memory circuit 12. In step 22d, the control unit 10 compares the analysis data with the reference data to determine a calibration deviation which is displayed on the VDU 15 in step 22e. Further, the control unit 10 determines the standard deviation using statistical algorithms and displays the standard deviation in graphical and numerical form in step 22f. Needless to say, everything which is output at the VDU 15 may also be down-loaded for printing at a printer to obtain a hard copy. In step 22g, the control unit receives an indication from a user at the keyboard 13 as to whether or not the deviation is acceptable for operation of the scanner 2.

If not, the control unit 10 displays a message on the VDU 15 prompting a user to re-calibrate the instrument. This latter step is indicated by the step 22h in Fig. 3. If, however, the deviation is acceptable, calibration of the scanner 2 is complete and the apparatus 1 is ready for use.

Before initiating analysis of a set of samples, standard samples are interspersed among the supplier's active samples and the control unit 10 receives at the keyboard 13 identification bar codes for the standard samples in step 23.

To analyse the samples, the conveyor belt 4 is activated and the bar code reader 5 reads the identification code in step 24 from the first sample which is presented. In step 25, the scanner 2 analyses the sample to determine the analysis data, namely, the butterfat, protein and lactose constituent levels of the sample. In step 26, the control unit 10 captures the analysis data from the scanner 2 and ' stores it in the read/write memory circuit 12. The control unit 10 then determines if the particular sample is an active sample from a supplier or a standard sample. If it is a standard sample, in step 27 the control unit 10 compares the analysis data and the reference data which is stored during the calibration steps 22. In step 28, the control unit 10 determines the deviation from the reference data and both numerically and graphically outputs this deviation.Accordingly, a user may monitor on an on-going basis calibration of the instrument and receive an advance warning if the instrument is approaching maximum calibration deviations. If the deviation exceeds pre-set maximum calibration deviations, the control unit 10 directs display at the VDU 15 of a warning message for a user in step 29. Further, the control unit 10 switches off the scanner 2 in step 30 to prevent further analysis of samples. It will thus be appreciated that quality of the analysed data is assured because the scanner 2 is not allowed operate while wrongly calibrated. The only precautions which are required of a user are to ensure that all samples which have been analysed since the previous standard sample should be reanalysed when the scanner 2 has been re-calibrated.

If the sample is not a standard sample, i.e. it is an active sample from a supplier, the control unit 10 compares the captured analysis data with the stored historical data in step 31 and if the difference is outside the stored sample tolerance limits, the control unit 10 directs display at the VDU 15 of a message indicating the difference in step 32. For example, this may show that water has been added to milk. In step 33, the bar code reader 5 of the scanner 2 determines if there are any other samples and if not, all of the analysis data, the differences from the historical data and the calibration deviations are stored by the control unit 10 in the fixed disc 11 in step 34. The process of analysing the batch of samples is then complete and the control unit 10 merges the stored data with pre-set report lay outs to generate management reports, and other documents.Referring to Figs. 4a to 4c, sample graphical outputs from the trace recorder 14 are illustrated.

In Fig. 4a, calibration deviations for fat content are illustrated for four samples. It will be noticed that for the fourth sample, the analysed constituent level exceeds the calibration upper limit, which would result in switching off of the scanner 2. The graph of Fig. 4b illustrates the calibration deviations for lactose content for four standard samples, for each of which the levels are within the calibration limits. In Fig. 4c, the calibration deviations for protein content are illustrated, and again, that for the last sample exceeds the maximum calibration limit.

It will thus be appreciated that the invention provides an analysis process which ensures that valid data is obtained, re-work is virtually eliminated and up-to-date reports may be readily easily obtained. This is particularly important where operations of a food processing plant are dependent on release of raw materials on a timely basis.

The invention is not limited to the embodiments hereinbefore described. For example, the analysis instrument may be an instrument for colony counting of bacteria of milk in petri dishes. In this embodiment the fact that sample codes are read and there is complete traceability of the samples is particularly important. Further, with such an analysis instrument the problem of "carry over" i.e. additional bacteria being counted in a following sample are avoided because of the manner in which calibration of the instrument is automatically checked according to the number of standard samples presented to the instrument.

The invention is not limited to the embodiments hereinbefore described, but may be varied in construction and details.

Claims (6)

1. A process carried out by a food analysis apparatus in analysis of a set of discrete food samples, the apparatus comprising an analysis instrument, a control unit for the instrument, storage means, a read/write memory circuit, a user input interface and a user output interface, the process comprising the steps of:: the control unit directing storage in the storage means of historical analysis data for active samples of a food, said historical analysis data being the data obtained on analysis of similar active samples on previous occasions; the control unit storing identification codes for standard samples of food; the control unit directing storage in the read/write memory circuit of reference data obtained from separate analysis of the standard samples; the control unit directing reading of an identification code of a sample presented to the instrument and capturing the identification code for storage in the read/write memory circuit; the control unit directing operation of the instrument for analysis of the sample and subsequently capturing analysis data of the sample for storage in the read/write memory circuit;; the control unit comparing the captured identification code with the stored standard sample identification codes to determine if the sample is an active or a standard sample; if the sample is a standard sample, the control unit comparing the analysis data with the reference data to determine a calibration deviation; the control unit directing output of the calibration deviation at the user output interface; if the sample is an active sample, the control unit comparing the analysis data with the historical data to obtain an active sample difference; the control unit directing output of the active sample difference at the user output interface.

2. A process as claimed in claim 1, comprising the additional step of the control unit directing calibration of the instrument, said process step involving the sub-steps of: the control unit directing storage in the storage means of reference data for standard samples; the control unit directing operation of the instrument for analysis of the standard samples; the control unit capturing analysis data of the standard samples; the control unit comparing the analysis data with the reference data to obtain a calibration deviation; the control unit directing output at the user output interface of the calibration deviation; the user input interface receiving an indication as to acceptability of the calibration deviation; and the control unit repeatedly directing output at the user output interface of a message directing re calibration of the instrument until receipt at the user input interface of an indication of acceptability of the calibration deviation.

3. A process as claimed in claims 1 or 2, comprising that the further steps of: the control unit directing storage in the storage means of a tolerance range for the difference between the analysis data and the historical data; and the control unit directing output of the difference at the user output interface.

4. A process as claimed in any preceding claim comprising the further step of the control unit switching off the instrument if the calibration deviation exceeds a preset minimum calibration difference.

5. A process as claimed in any preceding claim, comprising the further steps of the control unit directing storage in the storage means of all data written to the read/write memory circuit during operation on the instrument; and merging said data with pre-set report lay outs and generating reports at the user output interface.

6. A process substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.