Report on Staph Testing Methods and Results

 

Report on Staph Testing Methods and Results

 Sample ID: KHL2241

Lab: Hill Labs

Staph Test Result: 140 cfu/g

Method Details:

Automated Most Probable Number (MPN) count on TEMPO STA

Incubation at 35°C for 24-27 hours

Equipment: bioMérieux TEMPO

Detection Limit: <10 CFU/g

Specification as per Regulation: <50 CFU/g

Lab: Analytica

Staph Test Result: Not Detected/25g

Method Details:

Method: APHA 39.61

Detection Limit: Not Detected/25g

Specification as per Regulation: <50 CFU/g

Differences in Methods

Sample ID	Lab	Staph Test	Method Details	Detection Limit	Specification as per regulation
KHL2241	Hill labs	140 cfu/g	Automated MPN count on TEMPO STA, Incubated at 35°C for 1 24-27 hours. bioMérieux, TEMPO.	<10 CFU/g	<50 cfu/g
KHL2241L	Analytica	Not Detected/25g	APHA 39.61 method.	ND/25g	<50 cfu/g

Detection Technique:

Hill Labs: Uses an automated MPN count method with the TEMPO STA system by bioMérieux. This is a quantitative method where results are given in colony-forming units per gram (CFU/g).

Analytica: Uses the APHA 39.61 method. This method typically involves culturing and is often used for qualitative detection, resulting in a "not detected" (ND) output if no bacteria are found in the tested sample volume (25g).

Detection Limit:

Hill Labs: Can detect down to <10 CFU/g, providing a precise count if bacteria are present.

Analytica: Reports detection as "Not Detected" per 25 grams, meaning that if any Staph is present below the detection threshold in that sample size, it will not be detected.

Quantitative vs. Qualitative:

Hill Labs: Provides a specific count (140 cfu/g) indicating the exact level of contamination.

Analytica: Provides a qualitative result, indicating presence or absence without specifying the number.

Compliance with Regulations

According to New Zealand regulations, the release criteria for Staph levels in the tested product are set at <50 cfu/g.

Hill Labs Result: 140 cfu/g, which exceeds the regulatory limit.

Analytica Result: Not Detected/25g, which complies with the regulatory limit.

Summary and Recommendations

The method used by Hill Labs is more sensitive and provides a quantitative measure of bacterial presence. Their result indicates a level of contamination (140 cfu/g) that does not meet New Zealand’s regulatory criteria (<50 cfu/g).

Analytica’s method, being qualitative, detected no Staph in the 25g sample tested, thus complying with the regulations. However, it may not detect low levels of contamination that are above 50 cfu/g but spread out in a larger volume.

Given the discrepancy in results, it is advisable to:

·        Review the sampling procedures to ensure consistency.

·        Consider retesting the samples using the same method for both tests to ensure comparability.

·        If quantitative results are preferred for accuracy and compliance, the method used by Hill Labs could be considered more reliable.

****Note: Request Hill Labs to provide a report indicating results of <50 CFU/g instead of <10 CFU/g. For example, if the obtained value is around 22 CFU/g, please amend the specification value as per regulations.

·        Ensuring consistency in testing methods and understanding the sensitivity and specificity of each method will help in making informed decisions about product safety and compliance with regulatory standards.

        

 

         Reviewed By

Honey Expert & Technical Consultant IANZ Technical Expert BRCGS- Food quality & Safety Expert Ex. IANZ Authorized Representative Ex. Key Technical Person for Manuka Health & King Honey

 

Technical Specification Sheet: Honey Conversion Table

 

Technical Specification Sheet: Honey Conversion Table

1. Overview

This technical specification sheet provides a comprehensive conversion table illustrating the relationship between the % moisture, specific gravity, °Brix, and refractive index of honey at 20°C. The moisture content or soluble solids in honey are typically determined by measuring the refractive index using a refractometer.

2. Importance

The refractive index of honey differs from that of a sucrose solution at the same concentration, necessitating a unique moisture chart for accurate determination. This table assists in correlating these parameters to ensure precise measurement and quality control in honey processing and analysis.

3. Conversion Table

% Moisture	Specific gravity (20°C)	°Brix at 20°C (refractometer 0 - 90 range)	Refractive index at 20°C
13	1.4525	85.66	1.5041
13.2	1.451	85.45	1.5035
13.4	1.4495	85.24	1.503
13.6	1.4481	85.03	1.5025
13.8	1.4466	84.82	1.502
14	1.4453	84.61	1.5015
14.2	1.4438	84.39	1.501
14.4	1.4428	84.18	1.5005
14.6	1.4409	83.97	1.5
14.8	1.4395	83.76	1.4995
15	1.4381	83.55	1.499
15.2	1.4367	83.34	1.4985
15.4	1.4352	83.13	1.498
15.6	1.4338	82.92	1.4975
15.8	1.4324	82.71	1.497
16	1.431	82.5	1.4965
16.2	1.4295	82.29	1.496
16.4	1.4282	82.08	1.4955
16.6	1.4267	81.87	1.495
16.8	1.4254	81.66	1.4945
17	1.4239	81.45	1.494
17.2	1.4225	81.25	1.4935
17.4	1.4212	81.04	1.493
17.6	1.4197	80.83	1.4925
17.8	1.4184	80.63	1.492
18	1.4171	80.42	1.4915
18.2	1.4156	80.21	1.491
18.4	1.4143	80.01	1.4905
18.6	1.4129	79.8	1.49
18.8	1.4115	79.59	1.4895
19	1.4101	79.39	1.489
19.2	1.4087	79.18	1.4885
19.4	1.4074	78.97	1.488
19.6	1.406	78.77	1.4876
19.8	1.4046	78.56	1.4871
20	1.4033	78.35	1.4866
20.2	1.402	78.15	1.4862
20.4	1.4006	77.94	1.4858
20.6	1.3992	77.74	1.4853
20.8	1.3979	77.53	1.4849

Ref: Data from the table complied by H.D. Chetaway. National Research Laboratories - Ottawa. Temperature corrections are as follows: Specific Gravity = .0006 per °C or .00033 per °F; °Brix value = .09 per ° C or .05 per ° F; Refractive Index = .00023 per °C or .00013 per °F. If the temperature is above 20°C, add the correction; if it is below 20°C subtract the correction

4. Detailed Descriptions

% Moisture:

• Indicates the percentage of water content in honey.
• A critical parameter for assessing the quality and preservation of honey.

Specific Gravity (20°C):

• The ratio of the density of honey to the density of water at 20°C.
• Used to determine the concentration of soluble solids in honey.

°Brix at 20°C:

• Represents the sugar content of an aqueous solution.
• Measured using a refractometer, °Brix indicates the percentage of dissolved solids in honey.

Refractive Index at 20°C:

• A measure of how much light is bent, or refracted, when entering the honey solution.
• This parameter helps in identifying the concentration of soluble solids and moisture content.

5. Measurement Procedure

1. Sample Preparation:
• Ensure the honey sample is at a uniform temperature of 20°C.
• If necessary, warm the honey slightly to reduce viscosity and achieve a homogenous sample.
2. Using a Refractometer:
• Calibrate the refractometer according to the manufacturer’s instructions.
• Place a drop of honey on the refractometer prism.
• Close the prism cover and allow the sample to spread evenly across the surface.
• Read the refractive index directly from the refractometer scale.
3. Interpreting Results:
• Use the refractive index obtained from the refractometer to find the corresponding °Brix value from the table.
• Match the °Brix value to the specific gravity and % moisture content for precise analysis.

6. Application

This conversion table is essential for:

• Quality control in honey production.
• Ensuring compliance with food safety standards.
• Research and development in food science.
• Accurate labeling and marketing of honey products.

7. References

• The values in this table are derived from standard measurements and may vary slightly based on specific conditions and honey varieties.
• For further details, refer to industry guidelines and refractometer manufacturer manuals.

8. Notes

• Ensure all measurements are conducted at the specified temperature (20°C) for accuracy.
• Regular calibration and maintenance of refractometers are crucial for reliable results.

By following this technical specification, users can accurately determine the quality parameters of honey, ensuring consistency and compliance with industry standards.