Production of free fatty acids in safflower seeds by fungi

In 1975, free fatty acids (FFA) reached 0.50% in hand‐sampled seeds (achenes) from the Sacramento Valley but never exceeded 0.10% in samples from the San Joaquin Valley. High levels of FFA in safflower seeds from the Sacramento Valley were attributed to seed‐borne fungi, especially Alternaria sp., having a lipolytic action on safflower oil. Greenhouse inoculations on representative safflower cultivars reduced yields and oil content while increasing FFA. In vitro experiments using safflower oil‐potato dextrose agar medium showed that the Alternaria species and four other fungi isolated from safflower had lipolytic activity. The Alternaria sp. produced 3.90% FFA after 20 days of growth on this medium. Separation of the FFA by thin layer chromatography and characterization by gas liquid chromatography indicated that fatty acids are released by all five fungi in proportions similar to those in safflower oil.