Note 10 - Business Segment Reporting - Operations by Business Segment (Details) - USD ($)	3 Months Ended
	Aug. 30, 2015	Aug. 31, 2014
Packaged Frech Vegetables [Member]
Net sales	$ 103,706,000	$ 100,106,000
International sales	20,805,000	18,151,000
Gross profit	13,252,000	11,854,000
Net income (loss)	3,260,000	3,646,000
Depreciation and amortization	1,567,000	1,010,000
Dividend income	413,000	281,000
Interest income	6,000	11,000
Interest expense	467,000	338,000
Income tax expense (benefit)	921,000	870,000
Food Export [Member]
Net sales	22,344,000	26,597,000
International sales	22,344,000	26,587,000
Gross profit	1,003,000	1,186,000
Net income (loss)	101,000	271,000
Depreciation and amortization	$ 1,000	$ 1,000
Dividend income
Interest income
Interest expense
Income tax expense (benefit)	$ 28,000	$ 44,000
Biomaterials [Member]
Net sales	8,798,000	6,811,000
International sales	3,127,000	1,634,000
Gross profit	3,215,000	1,048,000
Net income (loss)	67,000	(1,542,000)
Depreciation and amortization	$ 605,000	$ 471,000
Dividend income
Interest income	$ 25,000	$ 71,000
Interest expense	35,000	45,000
Income tax expense (benefit)	19,000	(251,000)
Corporate Segment [Member]
Net sales	$ 507,000	$ 100,000
International sales
Gross profit	$ 507,000	$ 100,000
Net income (loss)	(476,000)	(22,000)
Depreciation and amortization	$ 38,000	$ 31,000
Dividend income
Interest income		$ 11,000
Interest expense
Income tax expense (benefit)	$ 723,000	$ 638,000
Net sales	135,355,000	133,614,000
International sales	46,276,000	46,372,000
Gross profit	17,977,000	14,188,000
Net income (loss)	2,952,000	2,353,000
Depreciation and amortization	2,211,000	1,513,000
Dividend income	413,000	281,000
Interest income	31,000	93,000
Interest expense	502,000	383,000
Income tax expense (benefit)	$ 1,691,000	$ 1,301,000