Development and Evaluation of a Portable Apparatus for Bioyield Detection: A Case Study with Apple and Peach Fruits

Figures & data

FIGURE 1 (a) Overall view and (b) schematic diagram of the bioyield apparatus developed.

TABLE 1 Characteristics of the 39 bioyield probes used for the bioyield measurement of apple and peach fruits

	Rubber tip thickness (t, mm)
	a = 1^[a]			b = 0.5			c = 0.25
Probe diameter (d, mm)	h = 3.9 MPa^[b]	m = 2.5 MPa	s = 1 MPa	h = 3.9 MPa	m = 2.5 MPa	s = 1 MPa	h = 3.9 MPa	m = 2.5 MPa	s = 1 MPa
A = 11.1	11.1	11.1	11.1	5.6	5.6	5.6	2.8	2.8	2.8
B = 9.5	9.5	9.5	9.5	4.8	4.8	4.8	4.2	4.2	4.2
C = 7.9	7.9	7.9	7.9	4.0	4.0	4.0	2.0	2.0	2.0
D = 6.4	6.4	6.4	6.4	3.2	3.2	3.2	<2^[c]	<2	<2
E = 4.8	4.8	4.8	4.8	2.4	2.4	2.4	<2	<2	<2

^[a]a, b, and c: thickness ratios (the ratio of rubber tip thickness to probe diameter);

^[b]h, m, and s: rubber tip elastic modules;

^[c]probe not used in tests.

FIGURE 2 Schematic diagram of a typical probe (t and d are thickness of tip rubber and diameter of probe, respectively).

FIGURE 3 Bioyield and MT firmness measurement locations at the equator of an apple (left) and of a peach (right).

FIGURE 4 Force-deformation curve for apple fruit under compression by one of the probes (4.8 mm dia., 2.56 MPa elastic modulus of rubber tip and rubber tip thickness of 4.8 mm).

TABLE 2 Relationship between the bioyield firmness (N) and MT firmness (N) for E probe with different tip designs at three loading rates (mm min⁻¹) for apples

Probe	Loading rate	Fitted equation	R square	RMSE (N)
E-am^[a]	3	MT = 1.24 By + 16.91	0.84	0.97
	6	MT = 1.70 By + 18.50	0.86	0.77
	9	MT = 0.97 By + 20.75	0.83	0.90
E-ah	3	MT = 1.63 By + 23.87	0.85	2.23
	6	MT = 2.02 By + 22.82	0.81	2.44
	9	MT = 1.12 By + 29.92	0.79	2.24
E-as	3	MT = 1.33 By + 18.54	0.75	1.70
	6	MT = 1.17 By + 18.51	0.80	1.43
	9	MT = 0.93 By + 21.04	0.81	0.93
E-bm	3	MT = 1.04 By + 22.08	0.76	1.51
	6	MT = 1.69 By + 16.36	0.74	1.53
	9	MT = 1.44 By + 19.14	0.68	1.29
E-bh	3	MT = 2.05 By + 29.62	0.85	3.92
	6	MT = 2.53 By + 23.03	0.79	3.48
	9	MT = 2.27 By + 25.13	0.73	4.60
E-bs	3	MT = 1.06 By + 21.99	0.77	1.79
	6	MT = 1.83 By + 15.57	0.78	1.86
	9	MT = 1.45 By + 19.16	0.80	1.11

^[a]E: probe diameter (4.8 mm);

a, b: thickness ratios of rubber tip (1 and 0.5, respectively);

h, m, and s: elastic modules of rubber tip (3.9, 2.5, and 1 MPa, respectively).

FIGURE 5 Correlation between MT firmness and bioyield force, using the selected probe (E-am) for apple fruit at 6 mm min⁻¹ loading rate.

TABLE 3 Relationship between the bioyield firmness (N) and MT firmness (N) for various probe designs at three loading rates (mm min⁻¹) for peaches

Probe	Loading rate	Fitted equation	R square	RMSE (N)
A-as	3	MT = 0.71 By + 0.81	0.73	0.179
	6	MT = 1.11 By + 1.16	0.74	0.159
	9	MT = 0.63 By + 0.87	0.73	0.135
A-bs	3	MT = 0.76 By + 0.72	0.73	0.212
	6	MT = 0.81 By + 0.54	0.72	0.171
	9	MT = 0.83 By + 0.52	0.76	0.167
A-cs	3	MT = 0.62 By + 0.80	0.69	0.185
	6	MT = 0.67 By + 0.74	0.69	0.210
	9	MT = 0.59 By + 0.79	0.66	0.172
B-as	3	MT = 0.81 By + 0.48	0.71	0.261
	6	MT = 0.68 By + 0.69	0.72	0.174
	9	MT = 0.68 By + 0.66	0.77	0.239
B-bs	3	MT = 0.70 By + 0.64	0.70	0.153
	6	MT = 0.67 By + 0.68	0.72	0.204
	9	MT = 0.64 By + 0.72	0.71	0.203
B-cs	3	MT = 0.75 By + 0.74	0.71	0.209
	6	MT = 0.71 By + 0.74	0.69	0.240
	9	MT = 0.74 By + 0.77	0.64	0.219
C-as	3	MT = 0.80 By + 0.69	0.75	0.200
	6	MT = 0.75 By + 0.72	0.72	0.176
	9	MT = 0.75 By + 0.76	0.71	0.180
C-bs	3	MT = 0.72 By + 1.06	0.72	0.167
	6	MT = 0.87 By + 0.86	0.70	0.186
	9	MT = 0.78 By + 1.01	0.68	0.149
C-cs	3	MT = 0.55 By + 1.08	0.70	0.198
	6	MT = 0.60 By + 1.06	0.66	0.192
	9	MT = 0.59 By + 1.06	0.69	0.204
D-as	3	MT = 1.16 By + 0.76	0.78	0.156
	6	MT = 1.30 By + 0.50	0.71	0.167
	9	MT = 1.19 By + 0.60	0.73	0.125
D-bs	3	MT = 1.11 By + 0.93	0.71	0.128
	6	MT = 1.15 By + 0.91	0.73	0.131
	9	MT = 1.13 By + 0.66	0.75	0.213
E-as	3	MT = 1.12 By + 1.13	0.72	0.205
	6	MT = 1.01 By + 1.19	0.73	0.137
	9	MT = 1.14 By + 1.09	0.76	0.114
E-bs	3	MT = 1.41 By + 0.92	0.74	0.213
	6	MT = 1.45 By + 0.96	0.73	0.226
	9	MT = 1.33 By + 0.98	0.72	0.211

^[a]A, B, C, D, and E: probe diameters (11.1, 9.5, 7.9, 6.4, and 3.9 mm, respectively);

a, b, and c: thickness ratios of rubber tip (1, 0.5, and 0.25, respectively);

h, m, and s: elastic modules of rubber tip (3.9, 2.56, and 1.00 MPa, respectively).

FIGURE 6 Correlation between MT firmness and bioyield force, using the selected probe (E-as) for peach fruit at 9 mm min⁻¹ loading rate.

FIGURE 7a Comparison of measured bioyield force by fabricated apparatus with the Instron, using the selected probe (E-am) for apple fruit at 6 mm min⁻¹ loading rate.

FIGURE 7b Comparison of measured bioyield force by fabricated apparatus with the Instron, using the selected probe (E-as) for peach fruit at 9 mm min⁻¹ loading rate.