Effects of Processing and Storage on the Folate Content of Spinach and Broccoli

Free and total folate activities (FFA and TFA) in spinach and broccoli were determined at various processing stages. In most cases FFA was significantly lower than TFA (P < 0.05). Steam‐blanching resulted in greater TFA retention than water‐blanching. Spinach lost 50% of the TFA during canning and another 10% after storage for 3 months. Storage at ‐ 32.2°C of water blanched spinach resulted in 27% TFA loss after 3 months and 17% TFA loss for water‐blanched broccoli after 8 months. For spinach and broccoli, 40% and 68%, respectively, of the TFA was in the blanch water but only 1% and 4% TFA, respectively, were in the steam‐blanch condensate. When canned, 14% of the TFA in spinach immediately after processing was in the liquid in the can. This amount increased to 18% after 3 months storage.