Kombucha ERP

Kombucha Method Re-submission Review Form

Submission Date

2018-11-19 19:43:55

Name

SNEH BHANDARI

Email

sneh.bhandari@mxns.com

Organization

Merieux NutriSciences

Candidate Method Number:

KOM-06

Has the resubmitted method met the requirements outlined on September 24, 2017? Please provide justification for your answer. If specific requirements were made in the September 24 meeting, please explain how those requirements have been met or not met.

No

1. Fruit juice is not in scope of the method. These matrices should be kept out of the method as well as the validation discussion. 2. No Kombucha sample data provided to substantiate listed LOD and LOQ calculated based on low-level concentration standard. LOQ which is verifiable in Kombucha matrices will be very relevant for applicability of the method in all relevant ranges of alcohol and in declaring the quantifiable limits. 3. Trueness (Bias) of the method has been evaluated using Cerilliant aqueous standards in the ange of 0.1-0.5%. It will help if the method accuracy could be demonstrated using other relevant fermented beverage reference materials like BCR 651 (Beer, ethanol = 0.505%), BCR 652 (Beer, ethanol = 0.051%) in absence of Kombucha. 4. The authors used four Kombucha samples for precision evaluation of the method as well as the spike recovery after spiking these samples with ethanol. They are identified as K1, K2, K3 and K4. The precision data in these samples are presented in Table 5 of the report. The ethanol levels in the samples estimated is in the range of 0.78-1.52% Abv. The spike recovery data on the same samples (K1, K2, K3, K4) are presented in Table 6 on page 24 of the report. Expected and measured alcohol in these samples is in the range of 0.26- 0.52%. Level of ethanol in spiked samples is lower than the same samples used for precision where ethanol is at higher level. The samples are identified as the same samples. A clarification will help to resolve this discrepancy. How did authors estimate the expected ethanol levels in samples K1 to K4 listed in Table 6. 5. The authors may add concentrations or enzyme activity details whichever is relevant to the reagents used in the method and listed on page 6 of the report. 6. The temperature of incubation is listed at 20°C listed in Step 5.8.5 of the method on page 8 may need clarification. The authors may clarify the acceptable range suitable for the method. 7. The authors may clarify the “Creep calculations” they refer on page 8 of the report. If the absorbance value has increased at this time, continue to read at 1- minute intervals until the rate of increase remains constant over a 5-minute period. 8. The authors on page 9 states that ΔA ethanol should be >0.1. What is the value ΔA ethanol value they obtained for Kombucha and blank samples.