Note 14 - Business Segment Reporting (Details) - Operations by Business Segment (USD $)	3 Months Ended		6 Months Ended
	Nov. 24, 2013	Nov. 25, 2012	Nov. 24, 2013	Nov. 25, 2012
Segment Reporting Information [Line Items]
Gross profit	$ 13,734,000	$ 18,459,000	$ 26,266,000	$ 32,222,000
Net income (loss)	3,451,000	8,913,000	8,203,000	13,279,000
Dividend Income	281,000	281,000	563,000	563,000
Interest income	46,000	33,000	105,000	58,000
Interest expense	436,000	498,000	867,000	1,039,000
Income tax expense	1,900,000		4,300,000
Food Products Technology [Member]
Segment Reporting Information [Line Items]
Net sales	88,090,000	78,592,000	167,526,000	147,223,000
International sales	10,345,000	5,959,000	19,823,000	12,182,000
Gross profit	8,220,000	13,102,000	17,101,000	23,045,000
Net income (loss)	2,005,000	9,212,000	9,271,000	15,128,000
Depreciation and amortization	1,304,000	1,174,000	2,526,000	2,410,000
Dividend Income	281,000	281,000	563,000	563,000
Interest income	2,000	7,000	5,000	8,000
Interest expense	356,000	427,000	732,000	882,000
Income tax expense	1,461,000	1,761,000	1,966,000	3,733,000
Food Export [Member]
Segment Reporting Information [Line Items]
Net sales	23,031,000	28,115,000	44,430,000	53,473,000
International sales	22,940,000	28,055,000	44,329,000	53,366,000
Gross profit	1,820,000	2,034,000	3,025,000	3,376,000
Net income (loss)	727,000	866,000	1,003,000	1,175,000
Depreciation and amortization	1,000	1,000	2,000	2,000
Income tax expense	205,000	288,000	283,000	391,000
HA-based Biomaterials [Member]
Segment Reporting Information [Line Items]
Net sales	8,777,000	7,740,000	17,363,000	15,713,000
International sales	3,366,000	4,222,000	7,743,000	9,024,000
Gross profit	3,625,000	3,116,000	6,013,000	5,482,000
Net income (loss)	611,000	338,000	235,000	26,000
Depreciation and amortization	604,000	592,000	1,188,000	1,175,000
Interest income	44,000	26,000	100,000	50,000
Interest expense	80,000	71,000	135,000	157,000
Income tax expense	172,000	113,000	66,000	9,000
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Net sales	128,000	207,000	186,000	319,000
Gross profit	69,000	207,000	127,000	319,000
Net income (loss)	108,000	(1,503,000)	(2,306,000)	(3,050,000)
Depreciation and amortization	36,000	38,000	71,000	74,000
Income tax expense	36,000	758,000	2,034,000	1,351,000
Total [Member]
Segment Reporting Information [Line Items]
Net sales	120,026,000	114,654,000	229,505,000	216,728,000
International sales	36,651,000	38,236,000	71,895,000	74,572,000
Gross profit	13,734,000	18,459,000	26,266,000	32,222,000
Net income (loss)	3,451,000	8,913,000	8,203,000	13,279,000
Depreciation and amortization	1,945,000	1,805,000	3,787,000	3,661,000
Dividend Income	281,000	281,000	563,000	563,000
Interest income	46,000	33,000	105,000	58,000
Interest expense	436,000	498,000	867,000	1,039,000
Income tax expense	$ 1,874,000	$ 2,920,000	$ 4,349,000	$ 5,484,000