Stability in Powder Form
Stability in powder form was studied to determine the shelf-life at room temperature. Two standardized commercial preparations equivalent to 15 × 109 and 6 × 109 cfu/g were considered for the study. The long term stability study of LactoSpore® was performed at room temperature according to ICH guidelines Q1A (R2) (ICH 2003).
There were very negligible reductions in spore counts of LactoSpore® in both samples compared with the respective initial counts, thus showing the stability of both the preparations over a period of 36 months (Majeed et al., 2016).
Heat Stability
Heat stability of probiotics is an important issue to be addressed when considering its addition to food items. Distinct characteristics about LactoSpore® are as follows:
- Due to spore-forming nature, it survives manufacturing, shipping and storage with no loss of viable count
- Does not require refrigeration conditions
- Room temperature stable
Trial #1: Temperature:90 °C (hot air oven) Duration: 30-150 sec
| Sample | TVSC (billion spores/g ) | Remarks |
|---|---|---|
| Control G80241 (15bs/g ) | 16.6 | 100% |
| 90 °C for 30 sec | 16.0 | 96.4% |
| 90 °C for 60 sec | 16.0 | 96.4% |
| 90 °C for 90 sec | 15.4 | 92.8% |
| 90 °C for 120 sec | 15.8 | 95.19% |
| 90 °C for 150 sec | 15.4 | 92.8% |
Trial #2: Temperature:90 °C (water bath) Duration: 30-180 sec
| Sample | TVSC (billion spores/g ) | Remarks |
|---|---|---|
| Control G80241 (15bs/g ) | 17.4 | 100% |
| 90 °C for 30 sec | 16.9 | 97.1% |
| 90 °C for 60 sec | 13.2 | 75.86% |
| 90 °C for 90 sec | 13.2 | 75.86% |
| 90°C for 120 sec | 14.5 | 83.33% |
| 90 °C for 160 sec | 14.2 | 81.60% |
| 90 °C for 180 sec | 14.3 | 82.10% |
Trial #3: Temperature:140 °C (hot air oven) Duration: 30-120 sec
| Sample | TVSC (billion spores/g ) | Remarks |
|---|---|---|
| Control G80241 (15bs/g ) | 17.9 | 100% |
| 140 °C for 30 sec | 17.4 | 97.2% |
| 140 °C for 60 sec | 15.7 | 87.71% |
| 140 °C for 90 sec | 13.6 | 75.98% |
Stability in Sugar Syrup
LactoSpore® sugar syrups containing 15 and 50 billion spores/g were stored at three different storage conditions for Total Viable Spore Count (TVSC) analysis:
- Accelerated (40 ± 2 °C, 75 ± 5% RH)
- Room Temperature (30 ± 2 °C, 65 ± 5% RH)
- Refrigerated (5 ± 3 °C)
Results indicated that almost 100% viability upto 24 months was observed under refrigerated condition.
Concentrated glucose syrup was prepared by adding 85 g of glucose into 15 g of water and slowly heated to 70 °C for 10 min then boiled for 10 min. After boiling glucose syrup, it was cooled down to 45–50 °C and then LactoSpore® (5.81% w/w of 300 x 109 CFU g-1 ) was added and blended for 30 min at low speed. Samples were analysed at 0, 1, 2, 3, 6, 12, 18 and 24 months (Majeed et al., 2016).
Stability in Baked Confectionaries
LactoSpore® was found to be stable during baking (for 20–25 min at 205 °C) and storage at frozen conditions (20±2 °C). Some examples include 92% viability when used in banana muffins and 86% viability when used in waffles up to 12 months (Majeed et al., 2016).
Stability During Coffee Brewing
The viability has been evaluated in coffee powder after brewing for 2 min followed by holding temperature 77 °C for 4 h. Only a 13% reduction (0.92 log10 CFU mL-1) was observed after brewing at 90 °C for 2 min from initial count (Majeed et al., 2016).
