Physicochemical properties and anthocyanin bioaccessibility of downy rose-myrtle powder prepared by superfine grinding

Figures & data

Table 1. Micromeritic and color properties of downy rose-myrtle powder

	Micromeritic properties					Color properties
Powders	D10 (μm)	D50 (μm)	D90 (μm)	Span factor	Specific surface area (m^2/g)	Lightness (L)	Redness (a)	Yellowness (b)
CP180	10.00 ± 1.01^a	86.93 ± 0.85^a	218.94 ± 2.21^a	2.35 ± 0.04^a	1.82 ± 0.01^a	42.36 ± 1.95^a	17.93 ± 0.48^a	3.90 ± 0.23^a
CP120	10.53 ± 0.83^a	73.19 ± 0.81^b	195.84 ± 1.89^b	2.46 ± 0.12^a	2.08 ± 0.01^b	45.66 ± 1.91^b	18.46 ± 0.32^a	4.61 ± 1.12^b
CP96	1.52 ± 0.67^b	46.56 ± 0.77^c	112.79 ± 1.52^c	2.62 ± 0.11^b	2.27 ± 0.02^c	46.63 ± 2.45^b	19.08 ± 0.43^b	6.77 ± 0.41^c
Superfine	0.79 ± 0.10^c	16.41 ± 0.23^d	41.57 ± 0.25^d	2.20 ± 0.03^c	3.14 ± 0.02^d	49.54 ± 2.71^c	18.99 ± 0.66^b	6.28 ± 1.26^c

The data are mean ± standard deviation, n = 3. Values in the same column with different letters are significantly different (P < 0.05).

Figure 1. SEM images of various particle sizes of downy rose-myrtle powders at 600 × magnification. (A) CP180; (B) CP120; (C) CP96; (D) superfine powder

Table 2. Physical properties of downy rose-myrtle powder

Powders	Bulk density (g/mL)	Repose angle (°)	Slide angle (°)	WHC (g water/g powder)	WSI (%)
CP180	0.62 ± 0.06^a	48.36 ± 1.08^a	49.13 ± 1.52^a	0.25 ± 0.01^a	33.50 ± 0.88^a
CP120	0.64 ± 0.05^a	49.26 ± 1.18^a	53.13 ± 2.33^a	0.26 ± 0.07^a	34.55 ± 1.05^a
CP96	0.54 ± 0.05^b	50.78 ± 1.23^a,b	60.84 ± 3.65^b	0.28 ± 0.01^a,b	36.91 ± 1.41^a
Superfine	0.49 ± 0.00^c	51.94 ± 1.23^b	70.24 ± 3.58^c	0.32 ± 0.01^b	45.39 ± 1.62^b

The data are mean ± standard deviation, n = 3. Values in the same column with different letters are significantly different (P < 0.05).

WHC, water-holding capacity; WSI, water solubility index.

Table 3. The release of polyphenols (mg GAE/100 g powder) from downy rose-myrtle powders before and after in vitro gastrointestinal digestion

Powders	Methanolic extract	Aqueous extract	Post gastric digestion	Post pancreatic digestion
CP180	898 ± 25^a	514 ± 16^a	645 ± 15^a	715 ± 16^a
CP120	903 ± 19^a	538 ± 11^a	648 ± 13^a	721 ± 14^a
CP96	952 ± 21^b	570 ± 12^a	657 ± 10^a	745 ± 18^a
Superfine	1132 ± 26^c	662 ± 21^b	784 ± 18^b	806 ± 23^b

The data are mean ± standard deviation, n = 3. Values in the same column with different letters are significantly different (P < 0.05).

GAE = gallic acid equivalents.

Table 4. The release of anthocyanins (mg CGE/100 g powder) from downy rose-myrtle powders before and after in vitro gastrointestinal digestion

Powders	Methanolic extract	Aqueous extract	Post gastric digestion	Post pancreatic digestion
CP180	76.8 ± 1.9^a	38.4 ± 0.6^a	55.2 ± 2.2^a	50.6 ± 2.9^a
CP120	79.5 ± 2.5^a	38.6 ± 0.8^a	54.8 ± 1.5^a	49.1 ± 2.3^a
CP96	80.3 ± 2.1^a	39.4 ± 1.0^a	60.4 ± 1.6^a	55.4 ± 2.6^a
Superfine	96.2 ± 3.2^b	54.8 ± 1.2^b	78.5 ± 2.9^b	72.2 ± 3.1^b

The data are mean ± standard deviation, n = 3. Values in the same column with different letters are significantly different (P < 0.05).

CGE = cyanidin 3-glucoside equivalent.

Figure 2. Polyphenols and anthocyanins bioaccessibility of downy rose-myrtle powders after in vitro gastrointestinal digestion. Values in the same group with different letters are significantly different (P < .05)

Figure 3. Evaluation of the antioxidant capacities of extracts from downy rose-myrtle powders as determined by ABTS radical scavenging effect. Values in the same group with different letters are significantly different (P < .05)