5.1.2.8 Yogurt
Yogurt may be contaminated by acid-tolerant fungi during the processing operation, including from added fruit preparations, especially yeast growth leads to blowing, off-flavors and off-odors, while post-acidification always occurs during cold storage, both will cause short shelf life thus consumer unacceptability.
 
Table 1 Handary Shelf life Solutions for Yogurt
Applications
Shelf-life diagnostics
Products
Labelled as
Dosage
Clean-label
Cost-in-use
5.1.2. 8 Yogurt
Anti-yeasts and molds
Natalac™ 
Natamycin (E235)
10-20mg/kg
Low
Low
Befresh™ AF
Lactobacillus Paracasei, Propionibacterium freudenreichii subsp shermani
10-20u/100L milk
High
Low
Stop over-acidification (e.g. Lactobacilli)
Epolyly
Polylysine
25-100mg/kg
Medium
Low
 
Table 2 Diversity of Spoilage Yeasts and Molds in Yogurt
Yeasts
Molds
 
Yeast and mold
Yeast and mold are major cause of spoilage of yogurt in which the low pH provides a selective environment for their growth. Yogurt having initial counts of yeast >100CFU/g (such as Candida spp., Kluyveromyces marxianus) tend to spoil quickly, resulting in fermented off-flavors and gassy appearance. Additionally, mold such as Penicillium spp. can also cause highly visible and pigmented growth in yogurt.
Atelosaccharomyces pseudotropicalis
Candida acidothermophilum
Candida beverwijkiae
Candida intermedia
Candida lusitaniae
Candida parapsilosis
Candida stellate
Candida versatilis
Debaryomyces hansenii
Dekkera anomala
Kluyveromyces marxianus
Peterozyma toletana
Saccharomyces cerevisiae
Yarrowia lipolytica
Naganishia albida
Rhodotorula diffluens
Rhodotorula mucilaginosa
Aspergillus section Nidulantes
Penicillium bialowiezense
Penicillium chrysogenum
Penicillium solitum
Mucor circinelloides
Mucor hiemalis
Mucor racemosus
 
 
NATURAL PROTECTIVE SOLUTIONS
SELECT THE PRODUCT TO FIND OUT MORE
Epolyly® Polylysine Stops Lactobacilli in Yogurt

Yogurt is an important and popular dairy product, of which stirred yoghurt is perhaps the main types, because lactobacilli in milk produce acid in low pH ranges, further acidification of yoghurt will occur and adversely affect the flavor, specifically, excessive acidity, which is unacceptable to the consumer, significantly influences the quality and shortens the shelf life, as an inhibitor for lactobacilli, Epolyly® addition after completion of the yoghurt fermentation can maintain the required quantity of active lactobacilli, keep the natural flavor, taste and viscosity, and extend the shelf life of yoghurt by more than 21 days.

To inhibit excessive fermentation, Epolyly® should be used at a level of 40-100 mg/kg, after the normal fermentation is completed, and the product has cooled, the Epolyly® should be dissolved in citric acid solution (pH 4.0), and should be gradually added to the yoghurt and mixed thoroughly.

Natalac™ Natamycin - cost efficient against yeast and mold in yogurt
Yeast and mold are major cause of spoilage of yogurt in which the low pH provides a selective environment for their growth. Yogurt having initial counts of yeast >100CFU/(Candida spp., Kluyveromyces marxianus) tend to spoil quickly, resulting in fermented off-flavors and gassy appearance. Additionally, mold such as Penicillium spp. can also cause highly visible and pigmented growth in yogurt.
 
The study shows that yogurt made with and without Natalac™ held 35 days at 5°C. Table 2 shows that an addition of 10mg/kg Natalac™ is effectively against yeast and mold in yogurt, extending the shelf life and protecting the nutrients with no impact on flavor.
 
Table 2 The comparison of yogurt with or without Natalac™ treated
Storage day
Yeast
Molds
Natalac™ 
Control
Natalac™ 
Control
3rd
ND
102
ND
102
7th
ND
3.7×102
ND
1.3×102
14th
ND
3.6×103
ND
3.6×103
21st
ND
4.3×103
ND
5.0×103
28th
ND
4.5×103
ND
2.8×103
35th
ND
5.5×103
ND
3.8×103

 

Befresh™ AF clean-label Antifungal cultures in yogurt

The study shows that yogurt made with and without Befresh™ AF held for 60 days at 5°C.  Figure 1 shows the yeast spoilage was inhibited, which leads to blowing, off-flavors and off-odors during the shelf life of yogurt. Figure 2 shows that the mold such as Penicillium spp. Was inhibited, which causes highly visible and pigmented growth in yogurt.

 Picture 1 shows the inhibiting effect of Befresh™ AF on molds in yogurt (7 days at 25°C, inoculate 1-2 mold spores on the surface of each sample).