Roasting is known to change the allergenic properties of peanuts. To study these observations at a molecular level, the relationship of IgE binding to the structure of Ara h 3 from raw and roasted peanuts was assessed. Ara h 3 (A3) was purified from raw (R), light roast (LR) and dark roast (DR) peanuts, the purity was assessed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the secondary structures were compared with circular dichroism (CD) spectroscopy. In order to understand the contribution of structure to IgE binding, the R A3 was partially denatured (PD) by heat treatment (65 °C for 2 h), subjected to CD spectroscopy and IgE spot blot analysis with sera from peanut- allergic individuals. While we observed that the secondary structure of purified A3 from R and LR peanut in solution was affected by the reduction of disulfide bonds and heat treatment when purified from the peanut following the roasting process, only small alterations were seen in the secondary structure. The purified LR A3 bound higher levels of IgE than the RA3. CD spectroscopy of PD A3 revealed a reduction in the percentage of alpha helices, and serum IgE binding. Therefore, while A3 purified from roasted peanuts did not show significant changes in secondary structure, it showed higher IgE binding than R A3. Therefore, the higher IgE binding to LR A3 was more likely to be due to chemical modifications than structural changes. However, a decrease in the IgE binding was seen if R A3 was deliberately unfolded, indicating that the structure played an important role in IgE binding to A3.

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The effects of maximum levels of selected additives in extra lean frankfurters (<3% fat) were studied. Seven treatments, with four replications each, were evaluated at three time periods (0, 30 and 60 days) in a randomized complete block design. The treatments consisted of: control; kappa‐carrageenan; hydroxypropyl methylcellulose (HPMC); high methoxy pectin (pectin); an acid modified food starch; sodium lactate; and acid enzyme deheated mustard. All treatment frankfurters had higher (P<0.05) yields than the controls. The pectin product had an unacceptable extremely soft, smooth pasty texture. Pectin and HPMC products had the lowest (P<0.05) purge at 60 days. In general, the addition of some appropriate additive or additives to low‐fat sausage products appears to be appropriate to increase processing yields, reduce cost and help bind free water so long as the additive or additives do not adversely affect other properties of the product.

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