Yogurt

Yogurt is 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

Items

Shelf-life issues

Solutions

Labelled as

Dosage

Clean-label

Cost-in-use

Yogurt

Inhibit yeast and molds

Natalac™ 

Natamycin

10-20mg/kg

Low

Low

Befresh™ AF

Lactobacillus Paracasei, Propionibacterium freudenreichii subsp shermani

10-20u/100L milk

High

Medium

Stop over-acidification

NisinZ® 

Nisin

40-100mg/kg

Medium

Low

 

NATURAL PROTECTIVE SOLUTIONS
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NisinZ® Vegetal NisinZ

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

Natalac™ Natamycin blends

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 (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 Antifungal cultures

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).