In a process involving the treatment of organic substances of vegetable or animal origin, which, in the presence of protein contained or introduced therein, exhibit proteolytic activity due to the presence therein of proteinases of the cell and tissue group (papain and cathepsin), the proteolytic activity is restrained or paralysed by the intimate incorporation in the substance of an oxidizing agent comprising at least one of the following: a halogen oxy-acid or its salt, or a per-acid or its salt.  The process may be employed to increase the keeping qualities of a substance, or to improve other qualities. Proteolytic decomposition of green vegetables during storage, or during the conversion into dried form, e.g. grass into hay, may be prevented.  A process for making gelatine from hides, slightly salted but not pretreated in any way and highly contaminated by offal from slaughter houses (internal organs containing tissue enzymes) is described.  The hides were finely cut and 100 kgs. were extracted for two hours at 40 DEG  C. by 250 litres of water to which were added 20 gms. of concentrated hydrochloric acid and 85 grms. of potassium bromate.  After the extraction, the residue was strained from the solution which set immediately it was left to stand.  Another 100 kgs. of hides were similarly treated except that no addition of potassium bromate was made.  The solution failed to set.  As an alternative, enzyme inhibitor 350 grms. of persulphate of ammonia was used with satisfactory results.  An experiment is described in which extract of malt having a good diastatic power but having too much proteolytic activity, which made the dough too soft when it was used for baking, was made satisfactory by adding to 100 kgs. of extract of malt, 130 grms. of potassium iodate.  British Specifications 2778/11, 1686/15, 235,874, 244,489, [all in Class 28 (i)], 340,072, 342,697, 375,679, [all in Group VI], and U.S.A. Specification 1,866,412 are referred to.  The direct addition of the oxidizing agents to dough is disclaimed.  The Specification as open to inspection under Sect. 91 discloses the restraining of proteolytic enzymes generally by the oxidizing agents. Also, the excessive proteolytic activity of dry yeast is restrained by adding potassium bromate thereto in the proportions 3 grms. of potassium bromate to 900 grms. of dried yeast.  The addition may be made by dissolving the bromate in the small quantity of water with which the dry yeast is mixed before kneading it into the dough, or, the oxidizing agent, in the form of a powder, may be mixed with the pulverized dry yeast, or added to the fresh yeast before drying it, or dusted into the flour to be used for producing the dough.  The inhibition of the proteolytic enzymes of the dry yeast avoids the soft dough normally obtained with the use of dry yeast.  This subject-matter does not appear in the Specification as accepted.ALSO:Proteolytic decomposition of green vegetables during storage, or during the conversion into dried form, e.g. grass into hay, is prevented by restraining the enzymes by the intimate incorporation therewith of an oxidizing agent comprising at least one of the following: a halogen oxyacid or its salt, or a per-acid or its salt.ALSO:In the manufacture of gelatine from hides &c., proteolytic enzymes of the cell and tissue group (papain and cathepsin) are restrained by an addition of at least one of the following: a halogen oxy-acid or its salt, or a per-acid or its salt. The hides, slightly salted but not pretreated in any way and highly contaminated by offal from slaughter houses (internal organs containing tissue enzymes) were finely cut and 100 kgs. were extracted for two hours at 40 DEG  C. by 250 litres of water to which were added 20 grms. of concentrated hydrochloric acid and 85 grms. of potassium bromate.  After the extraction, the residue was strained from the solution which set immediately it was left to stand. Another 100 kgs. of hides were similarly treated except that no addition of potassium bromate was made.  The solution failed to set. As an alternative enzyme inhibitor 350 gms. of persulphate of ammonia was used with satisfactory results.ALSO:The activity of proteolytic enzymes of the cell and tissue group (papain and cathepsin) are restrained by an addition of an oxidizing agent comprising at least one of the following: a halogen oxy-acid or its salt, or a per-acid or its salt.  An experiment is described in which extract of malt having a good diastatic power but having too much proteolytic activity, which made the dough too soft when it was used for baking, was made satisfactory by adding to 100 Kgs. of extract of malt, 130 gms. of potassium iodate.  The direct addition of the oxidizing agents to dough is disclaimed.  The Specification as open to inspection under Sect. 91 discloses the restraining of proteolytic enzymes generally by the oxidizing agents.  Also the excessive proteolytic activity of dry yeast is restrained by adding potassium bromate thereto in the proportions 3 grms. of potassium bromate to 900 grms. of dried yeast.  The addition may be made by dissolving the bromate in the small quantity of water with which the dry yeast is mixed before kneading it into the dough, or, the oxidizing agent, in the form of a powder, may be mixed with the pulverized dry yeast, or added to the fresh yeast before drying it, or dusted into the flour to be used for producing the dough.  The inhibition of the proteolytic enzymes of the dry yeast avoids the soft dough normally obtained with the use of dry yeast.  This subject-matter does not appear in the Specification as accepted.