Geometric and Mechanical Properties of Mung Bean (Vigna Radiata L.) Grain: Effect of Moisture

Figures & data

Table 1 Means and standard errors of the grain dimensions at different moisture content

Moisture content, % d.b.	Linear dimensions, mm			Average diameters, mm
	Length (L)	Width (W)	Thickness (T)	Arithmetic mean (Da)	Geometric mean (Dg)
7.28	5.145 ± 0.021 ^a	3.760 ± 0.014 ^a	3.537 ± 0.015 ^a	4.147 ^a	4.090 ^a
10.41	5.499 ± 0.006 ^b	3.988 ± 0.004 ^b	3.771 ± 0.004 ^b	4.419 ^b	4.357 ^b
12.60	5.704 ± 0.005 ^c	4.120 ± 0.004 ^c	3.903 ± 0.004 ^c	4.576 ^c	4.510 ^c
14.71	5.896 ± 0.005 ^d	4.268 ± 0.004 ^d	4.033 ± 0.004 ^d	4.732 ^d	4.665 ^d
17.77	6.199 ± 0.017 ^e	4.474 ± 0.012 ^e	4.223 ± 0.009 ^e	4.965 ^e	4.893 ^e
^a–eMeans superscript with different alphabets in the same column differ significantly (p < 0.05).

Figure 1 (A.) Effect of moisture content on sphericity of mung bean; (B.) effect of moisture content on surface area of mung bean; (C.) effect of moisture content on volume of mung bean; (D.) effect of moisture content on projected area of mung bean; (E.) effect of moisture content on thousand grains mass; and (F.) effect of moisture content on bulk density of mung bean.

Figure 2 (A.) Effect of moisture content on true density; (B.) bulk density variation with true density; (C.) effect of moisture content on porosity of mung bean; (D.) effect of moisture content on angle of repose of mung bean; (E.) effect of moisture content on terminal velocity; (F.) effect of seed moisture content on rupture force: (Δ) thickness; (◊) length; (□) width.

Table 2 Static coefficient of friction for mung bean

Moisture content, % d.b.	Coefficient of friction, μ
	Rubber	Galvanised iron	Medium density fibreboard	Stainless steel	Aluminium	Glass
7.28	0.386 (0.029) ^a	0.374 (0.010) ^a	0.360 (0.022) ^a	0.348 (0.018) ^a	0.344 (0.023)^ns	0.327 (0.017) ^a
10.41	0.402 (0.034) ^ab	0.384 (0.028) ^ab	0.368 (0.023) ^ab	0.358 (0.025) ^ab	0.350 (0.016)^ns	0.337 (0.014) ^ab
12.60	0.406 (0.037) ^ab	0.392 (0.030) ^ab	0.372 (0.036) ^ab	0.364 (0.032) ^ab	0.352 (0.017)^ns	0.337 (0.019) ^ab
14.71	0.410 (0.024) ^ab	0.404 (0.033) ^ab	0.380 (0.038) ^ab	0.372 (0.038) ^ab	0.356 (0.025)^ns	0.346 (0.015) ^b
17.77	0.433 (0.034) ^b	0.417 (0.034) ^b	0.392 (0.020) ^b	0.382 (0.041) ^b	0.362 (0.024)^ns	0.350 (0.023) ^b
Note: Values in the parentheses are standard deviation. ^a–bMeans superscript with different alphabets in the same column differ significantly (p < 0.05).

Table 3 Regression coefficients and coefficients determination for static coefficients of friction on different surfaces

Surface	Regression coefficients		Coefficient of determination (R^2)
	C1	C2
Rubber	0.3562	0.0041	0.94
Galvanised iron	0.3420	0.0042	0.99
Medium density fibreboard	0.3368	0.0030	0.98
Stainless steel	0.3243	0.0032	1.00
Aluminium	0.3324	0.0016	0.99
Glass	0.3113	0.0022	0.95

Table 4 Relationships between rupture force P_r> in N and moisture content of mung beans M_c> in % d.b. along the three major axes

Axes	Equation	Coefficient of determination (R^2)
Z (thickness)	Pr(T) = 89.09 – 2.6361Mc	0.95
Y (length)	Pr(L) = 80.536 – 2.1204Mc	0.97
X (width)	Pr(W) = 61.928 – 1.057Mc	0.92