The influence of a food-grade long-chain polyphosphate mixture on the growth and survival of spoilage micro-organisms during storage in an experimental processed cheese spread formulation was evaluated. The emulsifying salt was added to the cheese blend at a concentration of 0.5% or 1.0%. A control product was also manufactured, which contained monophosphate instead of polyphosphate as emulsifying salt, with all other ingredients being identical to those in the experimental processed cheese spread. Half of the finished products were subjected to accelerated shelf-life testing at 37 °C for 10 days, whereas the other half of them was stored refrigerated at 4 °C for 120 days. Microbiological analyses (enumeration of viable cell counts, mesophilic sulphite-reducing clostridia, coliforms, yeasts and moulds) and sensory tests were performed at regular intervals. The results showed that polyphosphates had a beneficial effect on the shelf-life of the processed cheese spread tested in that they significantly reduced (P<0.05) the growth or survival rates of spoilage bacteria, especially of mesophilic sulphite-reducing clostridia. Polyphosphates also beneficially influenced the sensory, including textural properties of the experimental processed cheese spread. All the samples containing less than 1% polyphosphate showed signs of butyric blowing significantly earlier (P<0.05), during both accelerated shelf-life tests and regular refrigerated storage, than did the products fortified with 1% polyphosphate. In conclusion, the suitability of the long-chain polyphosphate formulation tested for shelf life extension of processed cheese spreads was demonstrated.
widely studied IFRs system is the combination of ammonium polyphosphate, pentaerythritol, and melamine (APP/PER/MEL). There are many publications on the studies of the APP/PER/MEL compositions in polyolefin [ 1 – 10 ]. Bourbigot and co-workers have
Authors:F. Gomez, P. Vast, Ph. Llewellyn, and F. Rouquerol
We used CRTA for the study of both the elaboration and characterization of several polyphosphate glasses. We show that controlled transformation rate thermal analysis is able to remove a systematic error present in classical thermal analysis, in the study of the precursor of the phosphate glass. We show too that in CRTA, water release in the phosphate glasses can take place by diffusion phenomena at low temperature and that it is not due to the crystallization. These two examples illustrate some interests of this inverse method in the study of the decomposition of inorganic compounds with water release.
Authors:P. Melnikov, A. Guirardi, M. Secco, and E. Nogueira de Aguiar
Mechanisms of formation of polyphosphates MeIII(PO3)3, where MIII=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc, Fe, Ga, Al and Cr has been simulated by thermal analysis technique.
MeIII oxides and ammonium dibasic phosphate (NH4)2HPO4 were used as starting materials. For MIII=La-Lu, Y and Fe three main stages were observed: 1. elimination of water and ammonia leading to the formation of ammonium
tripolyphosphate (NH4)5P3O10; 2. reaction of the latter with Me2IIIO3 and formation of acidic polyphosphates MeIIIH2P3O10 or their isomers MeIII(PO3)3·H2O; 3. final loss of water and formation of MeIII(PO3)3. For MeIII=Sc and Ga the second stage is prolonged and the polyphosphates form at higher temperatures. Aluminum and chromium polyphosphates
are unstable. It is suggested that thermal behavior of the compounds is determined by MeIII ionic radii.
Interaction between iron(III)-diphosphate and iron(III)-triphosphate and Ca-form of a clayey meadow soil was followed over a period of three days using radiotracer technique and kinetic evaluation of the results performed.59Fe served to determine the quantity of iron,45Ca to measure the calcium, and phosphorus was measured spectrophotometrically. Approximately 80% of both iron chelates disappeared from the solution during the time of the experiment as a result of two well distinguishable reactions. One of them is a rapid interfacial process of about 10 minutes and the other is a slow reaction leading to the decomposition of iron(III)-polyphosphate chelates. The two processes could be separated using the Christiansen equation.
Authors:M. Veiderma, M. Pyldme, K. Tynsuaadu, and K. Utsal
The thermal interaction of Kovdor apatite, calcite, dolomite and forsterite with calcium polyphosphate up to 1200 °C were studied by chemical, thermal (under dynamic and quasiisothermal and isobaric conditions), X-ray, electronmicroscopic and chromatographic methods. It was found that the accompanying minerals of apatite react with calcium polyphosphate at lower temperature in comparison with apatite, complicating the process of thermal defluorination of papatite.
Authors:A. Squali, L. Montagne, P. Vast, G. Palavit, and J. M. Buisine
By thermobarometric analysis, we have investigated gels and coacervates of polyphosphates systems (x MO-y P2O5-z CaO-n H2O, whereM=Na or Mg) and studied their physico-chemical transformations until 1000 bars. In every case, the same general shape is obtained for the thermobarograms. A strong pressure increment is first observed bounded to the expansion of the sample under temperature effect. Then, between 100 and 110‡C, a free water release is detected by an important and progressive decrement of pressure issue from a strong volume decrement. At higher temperature, the hydrolysis of the systems is turned into pressure increments. Such experiments are the first showing that, by thermobarometric analysis, physico-chemical transformations can be easily studied. Moreover, for the first time, a negative volume change at a transformation obtained by increasing the temperature has been able to be observed by thermobarometric analysis.
Authors:A. Àgueda, S. Liodakis, E. Pastor, and E. Planas
The thermal degradation behavior of P. halepensis needles treated with two ammonium-polyphosphate-based commercial retardants was studied using thermal analysis (DTG) under
nitrogen atmosphere. Moreover, for the same experimental material, the heat of combustion of the volatiles was estimated based
on the difference between the heat of combustion of the fuel and the heat contribution of the charred residue left after pyrolysis.
The heat of combustion of the volatiles was exponentially related to the retardant concentration of the samples. In the range
of retardant concentrations from 10 to 20% w/w the mean reduction percentage of the heat of combustion of the volatiles, with
respect to untreated samples, was 18%.