Abstract: A method is provided for preserving cooking oil in a food fryer which comprises contacting the oil in situ with at least one oil-permeable cement body which is a stand-alone block and which has been hydraulically hardened from a paste comprising (i) white OPC clinker, (ii) white OPC or (iii) a mixture of white OPC clinker and white OPC, wherein the porosity of the cement body, estimable from the difference between its water-saturated and dry weights, is 30-55%, pores in the body being oil receptive by virtue of low un-bound water content.

Abstract: A method is provided for preserving cooking oil in a food fryer which comprises contacting the oil in situ with at least one oil-permeable cement body which is a stand-alone block and which has been hydraulically hardened from a paste comprising (i) white OPC clinker, (ii) white OPC or (iii) a mixture of white OPC clinker and white OPC, wherein the porosity of the cement body, estimable from the difference between its water-saturated and dry weights, is 30-55%, pores in the body being oil receptive by virtue of low un-bound water content.

Abstract: An hydraulically set oil-permeable cement body is provided in the form of a stand-alone block or briquette for preserving cooking oil during deep fat frying, said body. It has substantially no free water or having a low free water content for resisting damage on immersion in cooking oil and initial heating and is enclosed in packaging that resists ingress of water or water vapor The block or briquette consists of >50 wt % of a mixture of milled white OPC clinker and white OPC, optionally silica 1-2 wt % and/or titania (TiO2) 1-2 wt % and optionally further ingredients selected from calcium silicate, magnesium silicate, aluminum silicate, natural feldspars, natural sodium zeolites, natural calcium zeolites, synthetic sodium zeolites, synthetic calcium zeolites, wollastonite, calcium hydroxide, clays, pillared clays, activated clays/earths, talcs/kaolinite, amphiboles, granite porphyry, rhyolite, agalmatolite, porphyry, attapulgite and diatomaceous earth.

Abstract: An hydraulically set oil-permeable cement body is provided in the form of a stand-alone block or briquette for preserving cooking oil during deep fat frying, said body. It has substantially no free water or having a low free water content for resisting damage on immersion in cooking oil and initial heating and is enclosed in packaging that resists ingress of water or water vapour The block or briquette consists of >50 wt % of a mixture of milled white OPC clinker and white OPC, optionally silica 1-2 wt % and/or titania (TiO2) 1-2 wt % and optionally further ingredients selected from calcium silicate, magnesium silicate, aluminium silicate, natural feldspars, natural sodium zeolites, natural calcium zeolites, synthetic sodium zeolites, synthetic calcium zeolites, wollastonite, calcium hydroxide, clays, pillared clays, activated clays/earths, talcs/kaolinite, amphiboles, granite porphyry, rhyolite, agalmatolite, porphyry, attapulgite and diatomaceous earth.

Abstract: A method is provided for preserving cooking oil which may be cold or heated or during frying operations, which comprises in situtreatment of the oil withat least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement e.g. white OPC clinker and white OPC. The invention further comprises cooking oil having therein at least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement and an oil-permeable cement body for use in the above method.

Abstract: A method is provided for preserving cooking oil which may be cold or heated or during frying operations, which comprises in situ treatment of the oil withal least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement e.g. white OPC clinker and white OPC. The invention further comprises cooking oil having therein at least one oil-permeable cement body which has been hydraulically hardened from a paste comprising cement clinker and cement and an oil-permeable cement body for use in the above method.

Abstract: A method is provided for treating cooking oil during frying operations, which comprises in situ treatment of the oil with a source of calcium or magnesium combined with silicate such that the calcium or magnesium substantially does not leach into the oil. The filter treatment materials may be cement clinker, OPC, calcium silicate and combinations or mixtures thereof e.g. a combination of white OPC clinker and white OPC. The filter treatment materials may be in the form of a free briquette or block immersed in the oil. In other embodiments a decontaminating or filter cartridge is provided for fitting to a deep oil or fat cooker or a frying basket and comprises a foraminous housing containing filtering or decontaminant material. The cartridge may be used in association with a deep oil or fat fryer having a base formed with a depression defining a cool spot, the cartridge fitting in or on said cool spot.