Biosynthesis of Silver Nanoparticles by Polysaccharide of Leucaena leucocephala Seeds and Their Anticancer, Antifungal Properties and as Preservative of Composite Milk Sample

Table 4

Milk acidification (pH, alcohol precipitation, and heat coagulation) and proteolytic and lipolytic activity changes by E. coli, En. faecalis, L. delbrueckii subsp. Bulgaricus, and S. thermophilus at or in the presence of 25, 50, 100, or 200 μg mL^-1 AgNPs compared with negative control (lacking AgNPs) or positive control (formalin 0.4%).

Treatments	Beginning acidification time (min)		Alcohol precipitation time (min)		Heat coagulation time (min)		Beginning proteolytic activity time (min)		Beginning lipolytic activity (FFA production time) (min)
	37°C	43°C	37°C	43°C	37°C	43°C	37°C	43°C	37°C	43°C
Escherichia coli
Negative control
Positive control	—	—	—	—	—	—	—	—	—	—
25 μg mL^-1
50 μg mL^-1
100 μg mL^-1
200 μg mL^-1	—	—	—	—	—	—	—	—	—	—
Enterococcus faecalis
Negative control
Positive control	—	—	—	—	—	—	—	—	—	—
25 μg mL^-1
50 μg mL^-1
100 μg mL^-1
200 μg mL^-1	—	—	—	—	—	—	—	—	—	—
Lactobacillus delbrueckii subsp. Bulgaricus
Negative control
Positive control	—	—	—	—	—	—	—	—	—	—
25 μg mL^-1
50 μg mL^-1
100 μg mL^-1
200 μg mL^-1	—	—	—	—	—	—	—	—	—	—
Streptococcus thermophilus
Negative control
Positive control	—	—	—	—	—	—	—	—	—	—
25 μg mL^-1
50 μg mL^-1
100 μg mL^-1
200 μg mL^-1	—	—	—	—	—	—	—	—	—	—

Note (; ): values in rows with different superscripts (a–d) have significant differences according to Tukey’s HSD test at . – indicates that there is no change in tested parameters until 72 h.