FoodNet

A manual of home-making

1919

Page 325

Presented as published in 1919. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Any food in which the life processes are still going on is sub- ject to either of the types of changes just described. Yeast plants or bacteria may live on foods and cause them to spoil. Bacteria, yeasts, and molds grow ever>^where — on the ground, in w^ater, and in air. All micro-organisms need warmth, moisture, food, and oxygen for growth. Warmth, moisture, light, and oxygen also favor the maturing, ripening, and decay changes occurring in eggs, meat, fresh fruits, and vegetables. If food is to l>e kept for any length of time, it is necassary to retard or prevent natural ripening or <leveloping processes and to protect tfie foo<l from invasion i>y invisible as well as visible enemies. Metliods of foo<l preservation may be groupi?il as follow^sr (1) By means of low temperature; (2) the removal of moisture; (3) preservatives; (4) iiigh temperature* 679 680 A MANUAL OF HOME-MAKING A temperature even as low as the freezinp; jK>jnt of water mty not kill micro-organisms nor destroy in suvh foods as fruiu axii) vegetables the mibstancci^ that ripen and mature them* Such a temperature does, however^ retard or check all life prcxcBtnK and therefore it-s use is a highly efficient methocJ of k- ' un%\^ during limit tM:l periods of time. Refrigeration anil • ^rsp on a commercial scale are not discussed hen:% hut storage it moderately low temperatures that is practicaljle for the aveni^ home is descrit>ed. When foods are dried until their water-content is r^ui below 20 per cent, micro-organisms are not likely to develop i them. When foods are drit^cl, the micro-organiams orifcina present are not destroyt^l, hut their growth and muUiplic^atj' are checked. If nioLsture is supplied, active life quickly lic^nt! again. The word preserv^ative eovers a wide range of substances thai^ are used in food preservation to retard or prevent the rto^ of micro-organisms. Foods con tain ing any sul >stance siifBciitutl; active to destroy or check the growth of micro-organisms sh be at least thoroyghly questioned lief ore being used. Pre^^^ ative substances may be divided into three classes; (1) th< known to be harmless, sueli a.s sugar, salt, vinegar, and spv (2) those about which there is doubt, 6u<'h as saltpeter, 8nioki and liquid smoke; (3) those known (o be hannfiib sueh ag Ih>i acid and the l>orates, salicylic arid and the salieylati?®, ben acid and the benzoates, sulfunjus acid and the sulfites, and fonnaldehyde. The IJiitH States Department of Agriculture ha« i8BUcci the following statement concerning the use of canning powficr^ The pansibility of harmful effects from these suhstanceB is still not fully recognizetl by many housekeepers. **Thc att<?ntioti of the DepiirtTneni of Agriculture has reoeiitljr hmm called tfi the widespread u«c, oRpccinlly \n rur^ communities, of aiiSosrlb ftcid in putting up preserves. Th»* Df^purtmrnt i» aware tliat. this prMrtiBiy i» not confinefi to salicylic acid under it.>^ own name alone, tiiii lliai Iduv** quantities of this licid, ami uf U»rir, acid ai« vvi*ll, are sold under fjinaCtal lliitnc« iis prtftw^nnnjt powders or naaning compound* at prices whieli tDUch in excess of iheir real value. In the directions for use, the FOOD PRESERVATION 581