Soaking blanching

Figure 1. Structural changes of navy beans at various stages of processing la, dry bean lb, soaked/blanched bean lc, canned bean (scanning electron photographs S = starch granule P = protein bodies M = middle lamella)...

The blanched product is then soaked for 45-60 seconds in a vat containing 0.6% solution of sodium acid pyrophosphate (SAPP), solution maintained at 145°F (62.8°C). 

Preparation of dry beans involves preliminary hydration followed by various heat treatments to obtain a tender, palatable product. Water and heat play an important role in chemical reactions, heat transfer and chemical transformations, such as protein denaturation and starch gelatinization. Inadequate water uptake may result in insufficient heat transfer to inactivate antinutritional factors and result in reduced cookability. In general, beans with an initial moisture content between 12 and 18%, are soaked to hydrate the seed to a moisture content of 53 to 57% and subsequently blanched, cooked or canned. This cooking step, if done for an optimal time, renders the seed nontoxic, improves digestibility, develops acceptable flavor and softens the seed coat and cotyledon. 

Vegetables are acidified by soaking in an acid solution prior to processing, bulk storage in acid solutions, blanching in acid solution or direct addition of an acid brine. Acidifying soak water with citric or malic acid enhances the quality of canned dry beans (12) and dry lima beans (13). The occurrence of splits, drained weights, shear values, color and taste of dry beans were improved. 

Pick the young shoots and leaves in late spring and early summer. Add to soups and omelettes, or soak in salt water for an hour and blanch until tender. 

---