Use of hop cone extract obtained under supercritical CO₂ conditions for producing antibacterial all-purpose cleaners

Figures & data

Table 1. Compositions of prototypical formulations.

Component (INCI name)	Concentration (wt %)
Aqua	ad 100
Laureth-7	8.00
Sodium laureth sulfate	0.80
Sodium citrate	0.20
H. lupulus CO2 extract	0.00	0.01	0.10	0.30	0.50
Preservative	0.10

Table 2. Particle size in the test formulations.

Content of hop cone extract (%)	Peak 1		Peak 2		Peak 3
	Average particle size (±S.D.) (nm)	Intensity (%)	Average particle size (±S.D.) (nm)	Intensity (%)	Average particle size (±S.D.) (nm)	Intensity (%)
0.00	2.3 (±0.6)	84.9	32.3 (±7.8)	15.1	–	–
0.01	2.3 (±0.7)	84.2	32.0 (7.5)	12.8	2673 (±978)	2.0
0.10	2.1 (±0.9)	82.4	28.8 (±9.2)	11.2	2330 (±1178)	6.4
0.30	2.2 (±0.7)	78.4	25.6 (±8.3)	12.8	3026 (±1189)	8.9
0.50	1.8 (±0.5)	75.4	15.4 (±9.1)	14.3	3464 (±1249)	10.3

Figure 1. Turbidity of the formulations as a function of hop cone extract concentration.

Table 3. Mean values of colorimetric parameters for the test formulations.

Parameter	Concentration of hop cone extract (%)
	0.0	0.01	0.1	0.3	0.5
L	41.80 (±4.23)	41.75 (±4.53)	40.86 (±5.39)	37.88 (±5.28)	35.25 (±3.98)
a*	–0.81 (±0.22)	–1.33 (±0.25)	–2.25 (±0.19)	–2.58 (±0.28)	–3.08 (±0.27)
b*	2.67 (±0.34)	3.09 (±0.29)	13.63 (±0.43)	22.45 (±0.54)	24.81 (±0.52)

Figure 2. Changes in the total color difference (ΔE*) of the formulations as a function of hop cone extract concentration.

Figure 3. Antimicrobial activity of the test formulations against S. aureus ATCC 25923 (a); disc saturated with a formulation containing hop cone extract at the concentration of 0.5% (b).

Figure 4. Viable bacterial count and reduction of viable bacterial count.

Figure 5. Irritant effect of the formulations as a function of hop cone extract concentration.

Figure 6. Foaming properties of prototypical formulations.