Sweet Cheese Research Articles

ACCEPTANCE AND STABILITY OF CHOCOLATE AND STRAWBERRY FOUNTAIN SYRUPS MADE WITH CONCENTRATED, DECOLORIZED, DEIONIZED HYDROLYZED WHEY PERMEATE

Two lots of whey permeate from ultrafiltration of sweet cheese whey were deionized, decolorized, treated with a β-galactosidase to hydrolyze lactose and concentrated. The second lot was heated to 75 C following concentration to decrease the potential for sugar crystallization. Each lot of concentrated, decolorized, deionized hydrolyzed whey permeate (CHWP) was used in chocolate and strawberry fountain syrups as a partial or total sucrose replacement. Each syrup underwent organoleptic evaluation with comparison to a sucrose control. Samples of each syrup were also stored for 2 months at 4 C and 25 C. Chocolate syrups made with complete replacement by CHWP lots 1 and 2 scored very high but only syrups made with CHWP lot 2 were stable after 2 months storage. Strawberry syrups made with complete replacement by either lot of CHWP were sweet enough but scored poor in off-flavor intensity and overall preference. Syrups made with 50% replacement scored high in overall preference but poor in off-flavor intensity. Syrups made with greater than 50% replacement of sucrose became irreversibly crystallized and discolored after 2 months storage. CHWP had acceptable flavor and sweetness for use in highly flavored fountain syrups and should be economical to produce and be competitive with fructose and corn sweeteners.

Stability of Concentrated, Decolorized, Deionized Hydrolyzed Whey Permeate

Four separate lots of whey permeate from ultrafiltration of sweet cheese whey were deionized and decolorized to remove whey-like flavor and color, treated with β-galactosidase to hydrolyze lactose, and concentrated. Variables introduced were levels of lactose hydrolysis and total solids; storage temperature; order of deionization, hydrolysis, and decolorization processes; and use of a 75°C posthydrolysis heat treatment. Each batch was evaluated for microbial stability, resistance to crystallization, and flavor after 3 mo storage at 37°C.Concentration of permeate to less than 60% total solids resulted in microbial instability, and greater than 85% lactose hydrolysis resulted in galactose or lactose crystallization. Heating to 75°C and storing at elevated temperatures (up to 37°C) minimized crystallization. However, heating to 75°C accelerated browning. Flavor evaluation of browned samples suggested that caramelization rather than Maillard browning was the principal factor. Decolorizing with activated carbon after hydrolysis made no difference to the amount of sugar crystallization.Lactose hydrolysis improved the stability of concentrated, decolorized, deionized hydrolyzed whey permeate. The syrup with longest storage stability was decolorized, 90% deionized, contained 85 to 90% hydrolyzed lactose, was concentrated to 65% total solids, heated to 75°C following concentration, and stored at 30°C.

Acceptance of Frozen Desserts Made with Concentrated, Decolorized, Deionized Hydrolyzed Whey Permeate

Three separate batches of whey permeate from ultrafiltration of sweet cheese whey were deionized, treated with β-galactosidase to hydrolyze lactose, and concentrated. By varying the level of completion of these steps, by decolorizing the latter two batches, and by subjecting the last batch to a 75°C postpasteurization heat treatment, control of stability and flavor was increased.The concentrated, deionized, hydrolyzed whey permeate was divided into two lots, one of which was decolorized. The regular and decolorized permeates were then used in soft-serve ice milk, hardened ice milk, and milk shake mixes. Mixes were pasteurized at 77°C for 30min and stored at 4°C. After freezing, each underwent organoleptic evaluation and comparison with a commercial brand.Products made with regular permeate yielded satisfactory results when used only at low levels. Products made with decolorized permeate yielded better overall results, although the products were criticized for being less sweet than controls.A concentrated, deionized, hydrolyzed whey permeate product developed for sweetener applications should be economical to produce and should be highly competitive with fructose and corn syrup sweeteners.

Evaluation of hyperfiltration systems for sweet cheese whey. 2. Design studies and cost estimation

Part 1 of this paper showed the technical feasibility of using hyperfiltration with tubular membranes for whey concentration in a recirculation system or a single-pass system; here an economic evaluation is carried out in which, after an optimization procedure, both systems are compared. Both systems result in approximately the same permeate cost for the cases investigated, but the single-pass system was limited in volume reduction because of pressure-drop. As the two systems are economically comparable, the ultimate choice between them will be based on general advantages and disadvantages, and on considerations specific to the application. Investment cost for a hyperfiltration installation for whey concentration appears to be proportional to (feed-rate) 0.5. Permeate cost is proportional to (feed-rate) −0.32, based on 80% availability, 20 h production time per day and 4 h cleaning time per day. Electrical energy required ranged from 3·4 to 6·3 kWh m −3 permeate.

Preparation and purification of lactulose from sweet cheese whey ultrafiltrate

Description d'une methode de preparation directe de lactulose a partir du lactose et presentation de quatre methodes de purification. L'analyse par chromatographie liquide haute performance du lactulose obtenu montre un rendement de l'ordre de 80 %

Evaluation of hyperfiltration systems for sweet cheese whey. 1. Experimental results with a single-pass and a recirculation system

In a series of experiments, sweet cheese whey was concentrated by hyperfiltration, both with a single-pass system and a one-stage recirculation system. Process temperatures were 10, 18 and 30°C. In order to reduce membrane fouling, the pH of the whey was in most cases adjusted to about 6·0 by adding HCl. The single-pass system has a ‘tapered’ configuration and incorporated a booster pump. The drop in pressure and in flow velocity between entrance and outlet of the installation was only small in the recirculation system; in the single-pass system, however, it was considerable. With the single-pass system, the upper limit to volume reduction was about 60%, to a total solids content of 15%. For the recirculation system the upper limit was about 80% volume reduction, to a total solids content of about 28%. Measurements on residence time distributions showed that in the single-pass system plug flow was approached, while the one-stage recirculation system approximated to a perfect mixer. A semi-empirical mathematical model was developed to fit the experimental data. This model contains two adjustable ‘constants’ which were determined from the experimental data. The model enables local permeate fluxes to be predicted for a given set of process conditions, which makes such a model useful for design calculations.

Nutritional Evaluation of Cereal–Cheese Whey Mixtures

ABSTRACTThe chemical composition, amino acid content, PER, and digestibility of dehydrated sweet cheese whey, wheat flour, wheat bran, and lime‐treated corn flour (nixtamal, used for making tortillas), as well as of 21 cereal‐cheese whey mixtures were determined. The cheese whey was composed of 12% protein and 74% lactose. Diets containing a total of 8% protein were formulated with the cereal‐cheese whey mixtures. The 50:50 (% protein) cereal‐whey mixtures had the highest adjusted modified PERs, representing an increase over the cereals alone of 324% for the corn flour, 215% for wheat flour, and 177% for wheat flour, and 177% for wheat bran. The 50:50 (% protein) wheat bran mixture had the largest adjusted modified PER at 2.33 ± 0.13 (mean ± SEM) and the 50:50 wheat flour mixture, the smallest at 1.48 ± 0.21. Although the apparent digestibility was reduced from 10–14% for the latter two 50:50 cereal‐whey mixtures compared to the cereals alone, this was not reflected in the PER. It was concluded that the nutritive value of all the cereals tested significantly increased with the addition of 155 25% or more (by weight) of dehydrated cheese whey.

Scanning electron microscopy in the investigation of bite marks in foodstuffs

The purpose of the present study was to assess the value of utilizing SEM in the examination of bite marks in foodstuffs. Six students, whose front teeth showed no conspicuous irregularities, were asked to bite off a part of some selected foodstuff consisting of butter, cheese, Norwegian brown sweet cheese, apples, carrots, bananas, chocolate and chewing gum. The texture and the varying stickiness of the foodstuffs seemed to be of significance as far as the details of the bite marks were concerned. In butter, chewing gum and Norwegian brown sweet cheese, fine details were discerned, thus justifying the use of SEM. Both scratch marks of the front teeth and impression marks of the incisal edges were studied. Only the latter revealed details of value for the identification by means of the SEM. Often small enamel defects were found at the incisal edge of the front teeth. These defects showed a great number of individually characteristic details. Where dentin was exposed at the incisal edge, further characteristic details could also be found. Thus, the use of SEM seemed to be of value in special cases as a supplement to conventional investigation methods.

Interrelations of the Squash Bug, Anasa tristis, and Six Varieties of Squash (Cucurbita Spp.)1

Greenhouse studies involving interactions of six varieties of Cucurbita spp. and the squash bug, Anasa tristis (De Geer) (Corei dae, Hemiptera), indicate that Butternut is the most resistant and Black Zucchini is the most susceptible of the group. A smaller amount of plant sap was removed from the more resistant plants. Lack of preference appeared to be the major factor involved in resistance. However, the resistant plants produced an antibiotic effect on nymphal development. Nymphs reared on Black Zucchini and Pink Banana attained a significantly later instar and lived longer than those reared on the other four varieties. Tolerance did not seem to be involved in the greenhouse studies. The order of resistance of the six varieties from high to low was Butternut, Royal Acorn, Sweet Cheese, Green Striped Cushaw, Pink Banana and Black Zucchini.

Effect of Strain of Starter Culture and of Manufacturing Procedure on Bitterness and Protein Breakdown in Cheddar Cheese

Summary Eleven strains of Streptococcus cremoris were examined for their effect on bitterness in Cheddar cheese at six months of age. Four strains produced non-bitter cheese. The other seven strains produced bitter cheese, the intensity varying with the strain. According to nitrogen analyses of the cheese, strains producing bitter cheese hydrolyzed bitter-tasting peptides less extensively. The relation between bitterness and pH of cheese was studied by producing sweet and acid cheese with each strain, in addition to normal cheese. For each of the seven strains producing bitter cheese, bitterness in sweet cheese was less intense than in normal cheese, although sweet cheeses were often bitter. This experiment indicates that the selection of suitable strains for starter would control bitterness more satisfactorily than raising the pH of cheese. The results reconcile apparent anomalies between bitterness related to low pH and bitterness in cheese with a high pH. Strains were associated with significant differences in pH of cheese made by the same manufacturing procedure; these differences were unrelated to the intensity of bitterness. When the manufacturing procedure was changed to give cheese with a lower pH, the cheeses at six months of age generally contained greater amounts of acid-soluble, TCA-soluble and amino nitrogen. Differences in TCA-soluble nitrogen and in amino nitrogen were associated with the different strains.