Dairy Desserts Research Articles

Modeling the Kinetics of Physicochemical and Textural Qualities ofpantoa(Indian Dairy Dessert) During Deep-Fat Frying

The various physicochemical and textural qualities of pantoa (Indian dairy dessert) at different stages of deep-fat frying (DFF) were studied. Fat uptake was inversely related to moisture content. Pore formation during DFF resulted in an expansion ratio of 1.25–1.27, and a consequent decrease in apparent density from 1156 to 682 kg/m3. As crust formed, hardness of the product increased from 1.28 N to 6.29, 6.89 and 8.23 N at 125, 135 and 145C, respectively, after 480 s of frying. The influences of frying time and temperature on the physicochemical and textural attributes were predicted. Changes in moisture content and hardness, respectively, followed first and fractional conversion first order kinetics, while all other attributes were best described by a logistic model. The artificial neural network (ANN) models, with one hidden layer and 5–9 neurons were found to be superior to the mathematical models in predicting quality attributes as a function of process conditions. Also, using the physicochemical attributes of pantoa, its texture (hardness) was predicted using multiple linear regression and ANN models. Practical Applications Manufacture of pantoa is currently dominated by small-scale unorganized enterprises leading to non-optimized process conditions and widely varying product quality. The present study aims at describing the quality changes in the product during the deep-fat frying using mathematical models in a fryer. The effects of process parameters such as temperature and time on the various physicochemical and textural qualities were evaluated. The prediction of texture as a function of frying conditions, as well as, physicochemical attributes will be a useful and non-destructive method of evaluating quality. The mathematical models provide information to food processing professionals to help in optimizing the frying conditions of pantoa in order to maximize energy efficiency and consumer acceptance.

Tick front-of-pack label has a positive nutritional impact on foods sold in New Zealand.

Nutritional impact of the Tick front-of-pack labelling programme was evaluated by investigating nutrient changes to the purchased food supply and the nutritional quality of Tick v. non-Tick products. Factors influencing manufacturers' decisions to develop and license Tick products were also explored. Observational, cross-sectional and change over time data. New Zealand food supply, 2011-2013. Forty-five newly licensed Tick products from five food categories were analysed: Edible Oil Spreads, Yoghurt & Dairy Desserts, Frozen Desserts, Ready Meals and Processed Poultry. Four manufacturers of these products were interviewed. Eligible products (31 % of all Tick products in these categories) removed 4·1 million megajoules of energy, 156·0 tonnes of saturated fat, 15·4 tonnes of trans-fat and 4·0 tonnes of sodium from food products sold in New Zealand over three years. In each food category, these Tick products were, on average, 14-76 % lower in energy, saturated fat, trans-fat and sodium than non-Tick products, indicating healthier options. Participating manufacturers reported that international market trends and consumer demand for tasty, healthy foods primarily influenced Tick product development and sales. Tick was used as part of their marketing strategy as it was perceived as a credible, well-recognised logo for New Zealand consumers. Tick was cited as the primary initiative encouraging saturated fat reduction. The Tick Programme is continuing to encourage manufacturers to make meaningful improvements to the nutritional quality of the New Zealand food supply. Over time, these changes are likely to influence population nutrient intakes and reduce CVD risk factors.

The 5-CNL Front-of-Pack Nutrition Label Appears an Effective Tool to Achieve Food Substitutions towards Healthier Diets across Dietary Profiles.

BackgroundFront-of-pack (FOP) nutrition labels are considered helpful tools to help consumers making healthier food choices, thus improving their diet. In France, the implementation of a FOP nutrition label–the 5-Colour Nutrition Label (5-CNL)–is currently under consideration. Our objective was to investigate dietary profiles in a French adult population using the 5-CNL, and to assess its potential impact in improving the diet through substitution of foods.Methods and FindingsSubjects included in the NutriNet-Santé cohort, who had completed three 24-h dietary records were included in this cross-sectional analysis. Mutually exclusive clusters of individuals were identified using the percentage of energy derived from foods of each of the 5-CNL colours as input variables. Three scenarios of substitution of foods for healthier alternative using the 5-CNL were tested. Food group and dietary intakes, socio-demographic and lifestyle data were compared across clusters using ANOVAs or Chi-square tests, as appropriate. We identified three mutually exclusive dietary profiles: ‘Healthy’ (N = 28 095, 29.3% of the sample), with high consumption of fruit, vegetables, whole cereals and fish; ‘Western’ (N = 33 386, 34.8%); with high consumption of sweetened beverages, breakfast cereal, cheese, fatty and sugary foods; ‘Traditional’ (N = 34 461, 35.1%), with high consumption of potatoes, bread, meat and dairy desserts. Overall, substitutions strategies led to an increase in the number of subjects reaching the recommended intakes in energy, macro and micronutrients. Increases were particularly high in the ‘Western’ pattern for lipids and saturates intakes: from 16.2% reaching the recommended amount for lipids (13.5% for saturates) to 60.6% and 85.7% respectively.ConclusionThe use of the 5-CNL as an indicator of food choice meaningfully characterizes clusters of dietary habits and appears as an effective tool to help improving the nutritional quality of the diet.

Development of a LC–MS/MS method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche

A simple extraction, rapid routine method for the simultaneous determination of sorbic acid, natamycin and tylosin in Dulce de leche, a traditional South American product, by liquid chromatography–tandem mass spectrometry has been developed and fully validated. The limits of detection were set to 24.41mgkg−1 (sorbic acid), 0.10mgkg−1 (natamycin) and 2μgkg−1 (tylosin). Recoveries ranged from 95% to 110%. Proportionally, internal standardization was more efficient than external standard, resulting in a smaller measurement of uncertainty. In total, 35 commercial samples from Brazil, Argentina and Uruguay have been assessed. The proposed method was tested on other dairy desserts, demonstrating to be versatile. Although tylosin was not detected in any sample, a high rate of non-compliance was found, with 67.39% of samples above the maximum allowed for sorbic acid and a maximum concentration of 2105.36±178.60mgkg−1. In two samples, natamycin was irregularly found.

Effect of Ingredients and Processing Parameters on the Texture and Microstructure of Acid-Heat Coagulated Dairy Dessert

Dairy desserts obtained through heat and acid coagulation of milk are immensely popular in India. Cham-cham is one such dairy dessert prepared by cooking the drained milk coagulum (i.e., chhana), in sugar syrup. Slight variations in the formulation and processing parameters, such as powdered sugar addition to chhana, cooking syrup concentration, cooking time and soaking syrup concentration affects the quality of the product. Hence, the investigation was aimed at standardizing the processing parameters and to study the effect on texture, microstructure and sensory attributes of cham-cham. The cham-cham possessing maximum sensory scores were associated with hardness and moisture content of the product 11N and 36.62%, respectively. Principal component analysis applied to data matrix identified four principal components which explained 79.57% of variance in total. Scanning electron microscopy showed the changes that occurred in protein and fat phases of cham-cham as a result of cooking. Practical Application The standardized processing parameters may find application in large scale automated production of cham-cham by employing various equipments and machinery designed accordingly. Scanning electron microscopy of the product revealed that cow milk cham-cham possessed small fat globules which were not significantly ruptured during processing of cham-cham in boiling sugar syrup. Free fat released from ruptured fat globules may lead to decreased shelf life of the product due to free fat oxidation. The findings will help to manipulate the microstructure of cham-cham and to improve its texture.

Metabolic syndrome and dairy product consumption: Where do we stand?

Shifts in food composition and in dietary pattern as well as a modification in physical activity have led to increasing prevalence of overweight and obesity. Obesity is often accompanied by a cluster of metabolic abnormalities, termed the metabolic syndrome. Milk is an essential component of the human diet, and several dairy products resulting from processing of milk such as cheese, yogurt and dairy desserts are being consumed by millions of people worldwide. Consequently many studies were carried out on dairy products and their effect on body weight and fat, diabetes, metabolic syndrome (MetS), cardiovascular health, and bone health.Many epidemiological studies and a few meta-analyses on the relation between dairy product consumption and risk of metabolic syndrome were recently conducted using observational studies published up to March 2015. The evaluation of dairy consumption was carried out using food frequency questionnaires, food records and 24-h recall for most of the analyses so far published. As a general conclusion of the recent data, one may suggest an inverse relation between the consumption of dairy products and the prevalence of metabolic syndrome. However, it is still not very clear if all the dairy products have the same effects.Metabolomic technologies using targeted approaches have been used to unravel the identity of potential biomarkers of dairy product consumption. Some potential biomarkers such as fatty acids (15:0, 17:0, trans-16:1n−7) have been proposed to evaluate dairy product consumption. However, recently published papers raised concerns about using these fatty acids as potential biomarkers of dairy fat/dairy product intake. On the contrary, little has been published using metabolomic approaches on the potential metabolic effects of dairy products or on the relation between their consumption and the prevalence of metabolic syndrome or the associated pathologies.

Dairy Based Desserts are Negatively Associated with Bone Mineral Density among Puerto Rican Adults

BackgroundDairy foods have been shown to be protective for bone health, as these foods are a rich source of many nutrients known to be beneficial to bone. The majority of research on dairy and bone health has been conducted in Caucasian populations. It is important to study these associations in Latino populations as they are at high risk for developing osteoporosis. Further, their dietary patterns differ from other ethnic populations.ObjectiveTo examine the association of total dairy and dairy food groups with bone mineral density (BMD) among older Puerto Rican adults from the Boston Puerto Rican Osteoporosis Study, an ancillary study to the Boston Puerto Rican Health Study (BPRHS).MethodsDiet was assessed at baseline of the BPRHS by a food frequency questionnaire, adapted and validated for use in this population. BMD (g/cm2) was measured by whole body dual energy x‐ray absorptiometry at the hip and lumbar spine, L2–L4 approximately 2y after baseline. Participants were excluded if their t‐scores were greater than −4.0, and/or their total energy intake was >4,800 kcal/d or <600 kcal/d. Therefore, our total sample with bone, diet and covariate measures was 883 for models of the hip and 864 for the lumbar spine. Dairy intake was categorized into four groups: total dairy, fluid dairy (milk and yogurt), cheese, and dairy dessert (combined intake of the following: pudding, ice cream, cheesecake, custard/flan, cream). To account for total energy, all dairy groups were calculated as percentage of total energy intake. Tertiles of each dairy group were created, where tertile 3 (T3) represents the highest intake, and tertile 1 (T1) represents the lowest intake. Generalized linear regression compared adjusted least‐squares mean BMD across tertiles of dairy food groups.ResultsAverage age was 60±7y (range: 46–79); average BMI 32±7 kg/m2; and 73% of the sample were women. The median percent energy intake from each dairy group, by tertile was: total dairy, T1 6.0%, T2 11.6%, T3 18.6%; fluid dairy, T1 2.0%, T2 5.9%, T3 11.7%; cheese, T1 0.7%, T2 2.7%, T3 6.0%; dairy dessert, T1 0.1%, T2 0.9%, T3 3.3%. Total dairy intake was not associated with BMD at any site after adjustment for covariates (p‐trend range: 0.43–0.64). In dairy food group analyses, BMD at the hip and spine did not differ across tertiles of fluid dairy intake (p‐trend range: 0.24–0.66) or cheese intake (p‐trend range: 0.16–0.35). A significant, negative association was observed between high intakes of dairy dessert with BMD at the femoral neck (T2vsT1, p=0.02; T3vsT1, p=0.02); total femur (T2vsT1, p=0.02; T3vsT1, p=0.04) and lumbar spine (T3vsT1, p=0.04) (Figure).ConclusionsTotal dairy intake is not associated with BMD in older Puerto Rican adults, despite their relatively high percentage contribution to total energy. However, higher intake of dairy desserts is negatively associated with BMD. Further investigation will explore why dairy desserts contribute to lower BMD in this population.Support or Funding InformationP01 AG023394P50 HL105185R01 AG027087

Evaluation of process conditions and their optimization for baking of an Indian dairy dessert—chhana podo

ABSTRACTThe influence of baking temperature (120–150°C) and time (80–120 min) on selected physico-chemical and textural characteristics of chhana podo were investigated, and the baking conditions were optimized using response surface methodology. Crust and crumb moisture contents, total color difference, hardness, and specific volume were used as quality indices. The face-centered central composite design was used to study the effects of independent factors on the quality attributes. Moisture content decreased with baking temperature and time, while total color difference, hardness, and specific volume increased. The second-order polynomial models predicted the experimental responses adequately (% p < 5) and the lack-of-fit was not significant. The optimum conditions of baking were observed as 135ºC for 104 min. The crumb and crust moisture contents, specific volume, hardness, and total color difference of chhana podo were determined as 55.9%, 19.7%, 1.2 cm3/g, 22.7 N and 45.3, respectively.

Development of composition and technology of dairy dessert with carrot fiber

The development of modern traditional technologies of processing of plant raw material leads to a reduction of content in it of fiber. In this regard, it becomes necessary to create a category of products, which are additionally introduced functional ingredients. Conducted researches on studying possibility of using the carrot fiber in the production of dairy products in order to enrich the composition of them dietary fiber. At the initial stage of the study determined the effect of temperature and time of exposure to the swelling capacity of carrot fiber. Based on the organoleptic evaluation of various samples of dairy products with food fibers sour cream with fat mass fraction 20 and 25% is offered as a dairy basis for production of a dessert. The technique of introducing carrot fiber in a product is perfected and its optimal dose equal to 3% is selected. As a flavor filler used cocoa syrup, which is best combined with sour cream base. The research carried out to determine the ratio of cocoa powder and sugar in cocoa syrup, which will allow to obtain a product with a harmonious combination of the studied components. Flavoring fillers are chosen and the rational dose equal to 30% by weight of the product allowing to receive a dessert with high consumer properties is defined. It was found that it is expedient to introduce carrot fiber into the mixture to prepare syrup, because technological parameters of these transactions are almost similar. At the final stage of the study examined the effect of carrot fiber for a period of validity of the developed product. It was found that shelf life of developed product is not reduced compared with the control sample containing no dietary fibers.

Assessing infant exposure to persistent organic pollutants via dietary intake in Australia

Persistent organic pollutants (POPs) including polybrominated diphenyl ethers (PBDEs); organochlorine pesticides (OCPs); and polychlorinated biphenyls (PCBs) persist in the environment, bioaccumulate, and pose a risk of causing adverse human health effects. Typically, exposure assessments undertaken by modeling existing intake data underestimate the concentrations of these chemicals in infants. This study aimed to determine concentrations of POPs in infant foods, assess exposure via dietary intake and compare this to historical exposure. Fruit purees, meat and vegetables, dairy desserts, cereals and jelly foods (n = 33) purchased in 2013 in Brisbane, Australia were analyzed.For OCPs and PCBs, concentrations ranged up to 95 pg/g fw and for PBDEs up to 32 pg/g fw with most analytes below the limit of detection. Daily intake is dependent on type and quantity of foods consumed. Consumption of a 140 g meal would result in intake ranging from 0 to 4.2 ng/day, 4.4 ng/day and 13.3 ng/day, for OCPs, PBDEs and PCBs, respectively. PBDEs were detected in 3/33 samples, OCPs in 9/33 samples and PCBs in 13/33 samples. Results from this study indicate exposure for infants via dietary (in contrast to dust and breast milk) intake in Australia contribute only a minor component to total exposure.

The structure of a food product assortment modulates the effect of providing choice on food intake

Several authors showed that providing choice may increase food liking and food intake. However, the impact of choice may be modulated by assortment's characteristics, such as the number of alternatives or their dissimilarity. The present study compared the impact of choice on food liking and intake under the two following conditions: (1) when choosing a product to consume from among similar products versus dissimilar products; and (2) when choosing a product to consume from among pleasant products versus unpleasant products. Two experiments were carried out using the same design: the “apple puree” experiment (n = 80), where the volunteers choose from among similar products (apple purees varying in texture) and the “dessert” experiment (n = 80), where the volunteers choose from among dissimilar products (fruit dessert, dairy dessert, custard, pudding). During the first session, participants rated their liking for 12 products (apples purees or desserts). Then the participants were divided into a “pleasant” group (n = 40) in which volunteers were assigned three pleasant products, and an “unpleasant” group (n = 40) in which volunteers were assigned three unpleasant products. Finally, all of the volunteers participated in a choice session – volunteers were presented with their three assigned products and asked to choose one of the products, and a no-choice session – volunteers were served with one product that was randomly selected from among their three assigned products. Providing choice led to an increase in food liking in both experiments and an increase in food intake only for the desserts, namely only when the volunteers chose the product to consume from among “not too similar” alternatives. No effect of assortment's pleasantness was observed.

Prebiotic Low Sugar Chocolate Dairy Desserts: Physical and Optical Characteristics and Performance of PARAFAC and PCA Preference Map.

The addition of prebiotic and sweeteners in chocolate dairy desserts opens up new opportunities to develop dairy desserts that besides having a lower calorie intake still has functional properties. In this study, prebiotic low sugar dairy desserts were evaluated by 120 consumers using a 9-point hedonic scale, in relation to the attributes of appearance, aroma, flavor, texture, and overall liking. Internal preference map using parallel factor analysis (PARAFAC) and principal component analysis (PCA) was performed using the consumer data. In addition, physical (texture profile) and optical (instrumental color) analyses were also performed. Prebiotic dairy desserts containing sucrose and sucralose were equally liked by the consumers. These samples were characterized by firmness and gumminess, which can be considered drivers of liking by the consumers. Optimization of the prebiotic low sugar dessert formulation should take in account the choice of ingredients that contribute in a positive manner for these parameters. PARAFAC allowed the extraction of more relevant information in relation to PCA, demonstrating that consumer acceptance analysis can be evaluated by simultaneously considering several attributes. Multiple factor analysis reported Rv value of 0.964, suggesting excellent concordance for both methods.

Viability of probiotic micro-organism Lactobacillus acidophilus in dairy chocolate dessert and its action against foodborne pathogens

ABSTRACT: The ability to produce antimicrobial factors is considered an important feature of probiotic microorganisms. Bacteriocins, hydrogen peroxide, acetic acid and lactic acid are examples of these substances. The present research aimed to develop probiotic dairy desserts (DD) with Lactobacillus acidophilus and evaluate the viability of this strain, as well as its action on food pathogens. Treatments with and without interactions between L. acidophilus and pathogenic Gram-negative bacteria (Salmonella sp. and Escherichia coli O157:H7) and Gram positive (Bacillus cereus and Staphylococcus aureus) were produced. The products were stored at a temperature of 8°C and analyzed at the times 24, 48, 72 hours, 7 days and 28 days (at 28 days, only T1 was analyzed because the other products were deteriorated). In an analysis of the potential for development of new products, the dairy dessert with L. acidophilus was considered a probiotic product. Assessment of the counts of pathogens in dairy desserts with or without L. acidophilus showed different behaviors of these products in response to pathogens, which could be justified by a possible action of bacteriocins or microbial competition, but there has been no overall reduction or reduction up to a safe level. It is concluded that the probiotic products developed reduced significant food pathogens, but not up to safe levels. Thus, we emphasize the importance of the use of quality tools in the development and monitoring of dairy desserts.

Physicochemical assessment of fresh chilled dairy dessert supplemented with wheat germ

SummaryWheat germ is an available and economical source of protein, vitamins and antioxidants with an increasing application in food products. The main aim of this study was to investigate the effects of different levels (0.0, 2.5, 5.0, 7.5 and 10.0%) and particle sizes (120, 210 and 354 μm) of wheat germ on physicochemical properties of fresh chilled dairy dessert. With increasing wheat germ level, dry matter of the dessert increased while the pH decreased. Particle size had no significant effect on these parameters. Increasing the wheat germ content and particle size enhanced darkness, hardness, cohesiveness and gumminess of the desserts while decreasing springiness and water release of the samples. Wheat germ level had greater effects on different quality aspects of the desserts than its particle size. The most acceptable dessert was produced with no more than 5.0% wheat germ with either of the particle sizes used in this study.

USAGE OF CHITOSAN IN DAIRY PRODUCTS PRODUCTION

Abstract: The use of chitosan can significantly reduce energy costs in the processing of milk protein and carbohydrate raw materials, and is very promising for use in the dairy industry. In solution of serum proteins, the chitosan binds β-lactoglobulin and other proteins, thus forming an insoluble complex. The formation of complexes of proteins with the chitosan can be accompanied by both a change in the balance of forces that determine the nature of intra- and intermolecular interactions of protein globules, and formation of coacervates differing in size, shape, charge, degree of hydration. Electrostatic forces make the main contribution to the formation of the insoluble chitosan protein complex. In the study of the chitosan complexes formation conditions with the milk serum protein, the pH interaction was studied, as well as concentration of chitosan, the molecular mass of the polysaccharide, ionic strength, and other factors. These patterns of interaction of the milk serum proteins with the chitosan have formed the basis for the development of sorbents based on this polysaccharide. We studied the sorption properties of various forms of chitosan: granulated, as cryogels, as well as part of calcium tartrate gel. Using the chitozan containing sorbents allows us to select proteins from the milk serum and obtain purified preparations of β-lactoglobulin and lactoferrin. Inclusion of the chitosan in the milk beverages and dairy desserts allows us to create a functional food, where the polysaccharide acts as a technological, bactericidal and fungistatic agent.

Influence of Functional and Diet/Light Claims on Chocolate Dairy Dessert Consumers' Evaluations: Bilinear and Multilinear Decomposition Methods

AbstractThis study evaluates the effect of functional and diet/light claims on acceptance of chocolate dairy desserts. One hundred consumers participated in the tests of sensory acceptability in relation to the attributes of appearance, aroma, flavor, texture and overall liking. Tests were conducted using the same composition of samples and varying only the claims. Internal Preference map using parallel factor analysis and Principal Component Analysis (PCA) was performed using the consumer data. Data showed that consumers evaluated the claims differently. The samples with the addition of prebiotic claim and declaring the functional property of prebiotics were preferred by them. As the samples with the addition of diet/light claims, which received highest scores. It was concluded that the addition of claims may be suitable to be used in a chocolate dairy dessert with high acceptance by consumers.Practical ApplicationsThe role that food industry plays on people's everyday life is undeniable, as well as the importance of diet on the prevention of diseases and its association to health promotion. Food industry has amplified market by providing practical foods and goods for consumers’ convenience. The effect of information addition on the label of these foods is a study of great importance for food industries, as contributing to a better targeting of information, as the claims, and thus greater acceptance by consumers.

Multi-analytical approach for monitoring the freezing process of a milkshake based product

On or off-line controls of the freezing process, used to ensure the desired final quality of frozen dairy desserts, is an important task, especially for manufacturers who consider the standard of production as a primary goal. One of the products of interest in this context is the milkshake, a drink that contains ice crystals and a precise content of air. Herein, we used three different techniques, based on as many prototypes, to monitor and control the freezing process of a milkshake based product over a period of 1–29h: an optical technique based on a digital microscope and image analysis, a rotational rheometer and a capacitive device. The optical technique characterized crystal growth and air content during freezing, and can be regarded as a reference method. The dimension of ice crystals and content of air bubbles showed a non-linear increase during preparation time. Correlations were high, with coefficients of determination up to 0.991. Parameters measured by other techniques, such as a rotational rheometer and a capacitive device, also showed good, logarithmic correlations with freezing time, with R2 values up to 0.964. Correlations between the main freezing parameters and data obtained with the rotational and capacitive techniques appeared good (R2 up to 0.983). Thus, these latter techniques might conceivably replace more complicated and expensive optical methods used to monitor the freezing process, especially when processing a product characterized by a constant composition.

Dual modification of native white sorghum (Sorghum bicolor) starch via acid hydrolysis and succinylation

The present study investigated the effect of succinylation, acid-thining and combination of both on functional, textural and storage characteristics of starch isolated from white sorghum (Sorghum bicolor) grains. Prior to succinylation, native sorghum starch (NS) was acid-thinned with 0.1 M, 0.5 M and 1.0 M HCl solutions, separately. Succinylation of both NS and acid-thinned starches reduced percent retrogradation in starches while peak, cold paste and setback viscosities increased significantly. The extent of changes in various textural attributes like gumminess, hardness and chewiness were significantly reduced on refrigerated storage of starch gels. Similarly, decline in paste clarity was less pronounced in dual modified and single modified succinylated starches on cold storage. The results suggested that Su-At0.1M and Su-At0.5M starches showed lower percent retrogradation than At0.1M and At0.5M starches. Also they produced less gummy and chewy textures on storage which imply their application in puddings, custards and dairy desserts where weak gel formation is desirable. Also it was observed that Su-At1.0M gels had high degree of clarity, low hot paste viscosity and lower retrogradation tendency than At1.0M starches, which makes former extremely important in preparation of frozen pie fillings where high degree of clarity and storage stability is required combined with low hot paste viscosity.

Tunisian date (Phoenix dactylifera L.) by-products: Characterization and potential effects on sensory, textural and antioxidant properties of dairy desserts

Three Tunisian date varieties, Deglet Nour, Kentichi and Allig, served to produce syrups and powders, which were then examined for their physico-chemical composition and antioxidant properties. Different proportions of these sweetening-like agents were incorporated to produce nine different formulations of dairy desserts, with lower amount of added sugars to avoid any artificial flavoring or coloring agents. Sensory and color evaluation data revealed that incorporating Deglet Nour and Kentichi syrup offers the most desirable formulation. Furthermore, syrup polysaccharides and fibers contribute to better maintain the final product texture. In addition, date by-products create a good source of natural thickening agents, involved in enhancing apparent viscosity and spontaneous exudation. Thanks to their high content in phenolic compounds, date by-products considerably improve antioxidant activities of the formulated desserts. Therefore, they could be valued as natural ingredients in the formulation of novel dairy products with high nutritional-properties.

DETECTION OF ENTEROTOXIGENIC METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS IN DAIRY DESSERTS BY MULTIPLEX - PCR

The aim of this study is to evaluate the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) in dairy desserts samples and to investigate the antimicrobial resistance and molecular characteristics of these strains using PCR. A total of 120 samples comprising sweetened whipped cream, mehallabeia, ice cream and rice with milk were randomly collected from confectioneries, dairy shops, primitive restaurants and supermarkets in Sohag city, Egypt (30 samples each) and examined for presence of S. aureus. The results revealed that S. aureus could be detected in 23.3% of sweetened whipped cream, 6.7% of mehallabeia, 16.7% of ice cream and 3.3% of rice with milk samples. The results of antibiogram testing revealed that the highest percentage 9 (7.5%) of S. aureus isolates showed a complete resistance and 4(3.3%) showed intermediate resistance. However, the lowest percentage 2(1.7%) of the isolates were sensitive to methicillin. Eight out of nine strains that showed complete resistance using antibiotic sensitivity test identified as MRSA by detection of mecA gene by PCR (five from sweetened whipped cream, one from mehallbeia and two from ice cream samples). Furthermore, some classical enterotoxins gene profile of complete resistant strain were investigated by using M-PCR. The enterotoxins were detected in four strains only, and three different toxinotypes were recorded. The most frequent ones were “sea” gene, and followed by sed & seb from sweetened whipped cream and ice cream samples, while no sec gene could be detected from all samples. It is emphasized that the presence of S. aureus and their SEs genes in dairy desserts may be regarded as a potential risk for human health.