This document reports on research to develop cashew-coconut kefir yogurt using kefir grains. The objectives were to determine production parameters to suit Vietnamese preferences and characterize the resulting products. Various parameters were tested including milk ratio, coconut cream ratio, kefir grain ratio, and fermentation temperature. Sensory analysis found strained yogurt with cashews was most preferred. Microbial analysis showed unstrained kefir had higher bacteria counts due to higher water activity. Strained yogurt had lower carbohydrates and higher acidity, indicating longer shelf life. The optimal recipe used 0.75% kefir grains at 23°C for 24 hours with 20% coconut cream and a 2:1 milk to condensed milk ratio.

1. Research on development
and characterization of
Cashew-coconut yogurt
from Kefir grain
Nguyen Thanh Hang
Tu Minh Nhat
Nguyen Minh Thu
Pham Thu Trang
Nguyen Luong Bang

2. TABLE OF CONTENTS
01.
INTRODUCTION
03.
EXPERIMENTAL
METHODS AND
RESULTS
04.
CONCLUSION
02.
MATERIALS AND
PROCESSING LINE

3. Characteristics
of kefir grain
01
Objectives of
project
03
Kefir micro-
organisms
02
INTRODUCTION

4. Characteristics Of Kefir Grains
Strains of bacteria
Lactobacillus, Leuconostoc,
Acetobacter, Streptococcus and
Pseudomonas species
Differences
Colonize the intestinal tract >< yogurt
provide food for the healthy bacteria
found in the gut, keeping our digestive
tract clean.
Kefir yogurt
Acidic, light, thin, and
less creamy
Strains of yeast
Candida, Kluyveromyces
and Saccharomyces
species
Mesophilic
10oC – 40oC
Health benefits
Probiotic and prebiotic
Improve lactose tolerance,
06
05
04 03
01
02

5. Kefir micro-organisms
• Lactic acid bacteria (LAB) in kefir -> a pH decrease.
• Other kefir microbial constituents include lactose-fermenting
yeasts that produce ethanol and CO2.

6. OBJECTIVES
 Determine different parameters for kefir
production to cater for Vietnamese preference.
 Characterize kefir products by analyzing their
microbiological and physicochemical properties.

7. Materials and
Processing line

8. Materials
Kefir grains TH True milk
Sweet
Condensed
milk
Coconut
cream
Cashew nuts
Reduction of lactose
intolerance symptoms,
stimulation of the
immune system,
lowering cholesterol
Pasteurized milk is the
most popular choice
for culturing.
It improves flavor and
sweetness without
any graininess.
Use full-fat coconut
milk to get the
thickest, creamiest,
and overall best dairy
free yogurt
Nut-based yogurts are
an ideal source of fats
and protein

9. Processing line
Pasteurization:
 Destruction of pathogenic microorganisms.
Homogenization:
 Reduce the size of the fat globules.
 Increase the stability of the emulsion.
Filtration: Remove water out of yogurt to reduce lactose
content and get the desirable texture.
Blending: Adding cashew (3.3%) to improve flavors,
sensory attributes, and nutritional values.
Maturation: Improve flavor of kefir yogurt.
Storage: 4-6 °C for 14 days.

10. Experimental Methods And Results
Sensory
evaluation
Microbial
analysis
Chemical
analysis
Evaluation of different
parameters on kefir
yogurt production

11. Different Parameters On Kefir Yogurt Production
03 Kefir grain ratio
04 Fermentation temperature
02 Coconut cream ratio
Fresh milk ratio
01

12. Effect Of Fresh Milk Ratio On pH Of Final Product
COAGULATION
Earth is the third planet from
the Sun. We live on it!
SWEETENED
CONDENSED MILK
LACTOSE CONTENT
4.62
4.45 4.43
4.37 4.36
4
4.2
4.4
4.6
4.8
5
2 2.25 2.5 2.75 3
pH
Axis Title
Fresh milk/sweetened condensed milk: 2/1, 2,25/1, 2,5/1, 2.75/1, 3/1;
Coconut cream: 20%; Kefir grains: 1%; Temperature: 23oC, Time: 24h

13. Effect Of Coconut Cream Ratio On pH Of Final Product
Purposes
Reasons for the
decrease in pH level
Coconut cream
Time
20% 25%
20h 4.42 4.27
24h 4.19 4.04

14. 4.32
4.26
4.24
4.17
4.29
4.13
4.11
4.05
4.13
4.07
4.04
4.1
4.09
4.05
4.01
3.85
3.9
3.95
4
4.05
4.1
4.15
4.2
4.25
4.3
4.35
18 20 22 24
pH
FERMENTATION TIME
0.50% 0.75% 1% 1.50%
Effect Of Kefir Grain Ratio On pH Of Final Product
Fresh milk/sweetened condensed milk: 2/1; Coconut cream: 20%;
Kefir grains: 0.5%, 0.75%, 1%, and 1.5%; Temperature: 30oC;
Time: 18h, 20h, 22h, 24h
TIME
DOSAGE OF KEFIR GRAIN
Kefir grain, pH
Time, pH

15. 5.13 5.11 5.06
5.01
4.92
4.7
4.5
4.41
4.3
3.8
4
4.2
4.4
4.6
4.8
5
5.2
20 22 24
pH
FERMENTATION TEMPERATURE
20oC 23oC 25oC
Effect Of Temperature On pH Of Final Product
Fresh milk/sweetened condensed milk: 2/1; Coconut cream: 20%;
Kefir grains: 0.75%; Temperature: 20oC, 23oC, 25oC;
Time: 20h, 22h, 24h
TEMPERATURE
TIME
Temperature, pH
Time, pH

16. Sensory
evaluation

17. SAMPLES
Strained Unstrained Strained Unstrained
No cashew Cashew

18. PROPERTIES
TASTE
Sour Coconut cream
Sweet Cashew
TEXTURE
Viscosity
Thickness
APPEARANCE
Air bubbles
Cashew
OVERALL LIKING
FEELING WHEN EATING
Alcohol level
SMELL
Yogurt
Coconut cream

19. Sensory
evaluation results

20. Comparison of Cashew

21. Comparison between Unstrained and Strained

22. Microbial and
chemical analysis

23. Chemical Properties Analysis
Chemical
properties
pH and TA value
pH: measured at day 1,7
- TA: measured at Day 1,7
- 10g Sample + 10ml distilled water and titrated-> light pink with 0.1
NaOH
- Stored at 4C
- During titration: NaOH injected -> lactic acid: 𝑡 =
𝑉𝑥10
𝑚
Quantification of
carbohydrate
1ml sample + 100ml distilled water
2g D-glucose + 100ml distilled water -> 200µg/ml concentration
D-glucose solution (40,80,120,160,200,240) + 2ml tubes
Tubes 1: blank; tube 8,9: 2 unknow samples of 2 kefir types (strained,
unstrained)
1000µL H2SO4 98% each tube + 200µl 5% Phenol => incubate
(90°C,15min)

24. Microbial Analysis
Microbiological
analysis
Aerobic bacteria;
LAB; yeast
enumeration
Aerobic bacteria: TSA + 10% antifungals
LAB enumeration: MRS + 10% antifungals
Incubated: 35 °C; 48h
Yeast-mold count Sabauroud agar + 1g antimicrobials Incubated: 35 °C; 48h
Total coliform
bacteria
VRBL culture
Incubated: : 35 °C; 48h
Dark-red colonies with d= 0.5-2mm

25. Microbiological Analysis
ND: not detected
Note: The results are the mean of three replications. The difference between the
averages with the same letter in the same row was not statistically significant
(P > 0.05).
Sample
Microorganisms
Strained kefir
(Log (CFU/ml))
Unstrained Kefir
(Log (CFU/ml))
LAB 7.40 ± 0.18b 7.78 ± 0.06a
Aerobic bacteria 7.23 ± 0.09b 7.73 ± 0.03a
Yeast 5.19 ± 0.02a 4.9 ± 0.02b
Coliforms ND ND
BACTERIA: 7 log(CFU/ml)
YEAST: 4 log(CFU/ml)
(Codex Stan 243-
2003)

26. Sample
Microorganisms
Strained kefir
(Log (CFU/ml))
Unstrained Kefir
(Log (CFU/ml))
LAB 7.40 ± 0.18b 7.78 ± 0.06a
Aerobic bacteria 7.23 ± 0.09b 7.73 ± 0.03a
Yeast 5.19 ± 0.02a 4.9 ± 0.02b
Coliforms ND ND
Microbiological analysis
→ Higher water activity in unstrained kefir
provides better bacterial growth
Difference in
water activity:

27. Sample
Microorganisms
Strained kefir
(Log (CFU/ml))
Unstrained Kefir
(Log (CFU/ml))
LAB 7.40 ± 0.18b 7.78 ± 0.06a
Aerobic bacteria 7.23 ± 0.09b 7.73 ± 0.03a
Yeast 5.19 ± 0.02a 4.9 ± 0.02b
Coliforms ND ND
Microbiological Analysis
Inhibits bacteria: Escherichia
coli, Listeria monocytogenes,
Salmonella spp., and others.
Synergistic effects of inhibitory
compounds such as
bacteriocins, hydrogen peroxide,
or organic acids (Kim et al.,
2016)

28. Chemical Properties
Note: The results are the mean of three replications.
The difference between the averages with the same
letter in the same row was not statistically significant
(P > 0.05).
Higher number of bacteria
Sample
Day no.
Strained Kefir
Unstrained
Kefir
Day 1 4.61 ± 0.02a 4.32 ± 0.01b
Day 7 4.27 ± 0.13a 3.77 ± 0.05b
pI (casein) 4.6 – 4.8 (Głąb & Boratyński, 2017)
pH (kefir grains)
4.2 - 4.6 (Ribeiro et al., 2020))
Better protein structure and
environment for microbial growth

29. Chemical Properties
Note: The results are the mean of three replications. The
difference between the averages with the same letter in the
same row was not statistically significant (P > 0.05).
Sample
Day no.
Unstrained
Kefir (ml/g)
Strained Kefir
(ml/g)
Day 1 2.17 ± 0.1b 2.4 ± 0.1a
Day 7 8.5 ± 0.15b 9.8 ± 0.2a
LACTIC ACID
CONCENTRATION
> normal yogurt (1.8–2.0% as
lactic acid) (Lange et al., 2020)
Inhibit the growth of bacterial
pathogens
Longer storage of the strained
products.

30. Quantification Of Carbohydrate
Unstrained yogurt might be an ideal for those who seek to reduce
carbohydrate in their meal.
Not comply with information from Food Data Central on Greek and
plain yogurt, which indicates that the carb in Greek is normally half of
that in unstrained yogurt  further research on sugar metabolism
rate.
Type of yogurt Carbohydrate concentration (g/ml)
Unstrained yogurt 0.124 ± 0.011c
Strained yogurt 0.167 ± 0.004a
Vinamilk sweetened yogurt 0.156 ± 0.006b

31. CONCLUSION
0.75% of kefir grains per 100g milk
20% coconut cream per 100g milk
The ratio between condensed milk and milk was 1:2
The process was performed at 23oC for 24h.
3. Strained yogurt improved texture and taste.
2. Products with cashew were the most preferred
1. Most optimal recipe:

32. REFERENCES
Kim, D. H., Jeong, D., Kim, H., Kang, I. B., Chon, J. W., Song, K. Y., & Seo, K. H. (2016). Antimicrobial activity of kefir against
various food pathogens and spoilage bacteria. Korean Journal for Food Science of Animal Resources, 36(6), 787–790.
https://doi.org/10.5851/kosfa.2016.36.6.787
Głąb, T. K., & Boratyński, J. (2017). Potential of Casein as a Carrier for Biologically Active Agents. Topics in Current Chemistry,
375(4). https://doi.org/10.1007/s41061-017-0158-z
Ribeiro, A. C., Lemos, Á. T., Lopes, R. P., Mota, M. J., Inácio, R. S., Gomes, A. M. P., Sousa, S., Delgadillo, I., & Saraiva, J. A.
(2020). The combined effect of pressure and temperature on kefir production—A case study of food fermentation in
unconventional conditions. Foods, 9(8), 1–13. https://doi.org/10.3390/foods9081133
Lange, I., Mleko, S., Tomczyńska-Mleko, M., Polischuk, G., Janas, P., & Ozimek, L. (2020). Technology and factors influencing
Greek-style yogurt – a Review. Ukrainian Food Journal, 9(1), 7–35. https://doi.org/10.24263/2304-974x-2020-9- 1-3