The effect of cheese powder in the functional properties of croissant pastry : a thesis presented in partial fulfilment of the requirements of the degree of Master of Technology in Food Technology at Massey University

The increasing use of cheese powder as an ingredient used by food manufactures can be related to the changing consumer needs, identifying new consumer preferences, marketing and obtaining an acceptable capital return. Cheese powder have been used in bakery products to improve their functional properties and impart flavour. Therefore, the development of cheese flavoured croissants was chosen to increase the utilization of cheese powder in the formulation croissant pastry. For this reason, the New Zealand Dairy Board (NZDB) predicted a brighter future for this type of dairy ingredient because of its dual acceptability of providing important functional characteristics and its cost advantage over other dairy products. The addition of cheese powder to croissant pastry resulted in affecting the dough's physical properties and baking characteristics; i.e, increasing the dough elongational viscosity, decreasing the farinograph absorption values, decreasing the specific volume of baked croissants, and croissant firmness results indicating significant differences as a function of time for storage. Cheese croissants containing ten percent level of Cheddar-20 cheese powder was found to be the only one to have statistically significant differences in most of the attributes compared to CP1 and CP2 cheese powder when used in the formulation. Ten percent level of cheddar-20 cheese powder received the highest score and preferred by 77.8% of the panellists. Therefore, the ten percent of cheddar-20 cheese powder level was chosen for further development including the determination of the new cheese powder mixing method with its time-temperature relationship and evaluation of the market trial. The new cheese powder mixing method (3% cheese powder mixed with dry ingredients, and 7% used to produce cheese paste) during which the paste was applied over the laminated dough and the cheese powder combined with the dry ingredients improved the cheese croissant quality characteristics when compared to the other mixing method (total 10% cheese powder mixed with other dry ingredients). The baking time-temperature relationship of the new cheese powder mixing method was twenty seven minutes at 275°F which gave the best quality characteristics for high volume, a golden brown crust colour and flaky texture. This method received the highest scores and the most acceptable cheese croissant by the panellists. The market evaluation results indicated that 87% of potential consumers preferred the cheese croissants. The total sales potential indicated to be approximately 2.000 tonnes/annum of finished product with a population of ten percent of the market share. The estimated net present value over five year product life was $3,206,000

Temporal and spatial differences in microbial composition during the manufacture of a Continental-type cheese

peer-reviewedWe sought to determine if the time, within a production day, that a cheese is manufactured has an influence on the microbial community present within that cheese. To facilitate this, 16S rRNA amplicon sequencing was used to elucidate the microbial community dynamics of brine salted Continental-type cheese in cheeses produced early and late in the production day. Differences in microbial composition of the core and rind of the cheese were also investigated. Throughout ripening, it was apparent that late production day cheeses had a more diverse microbial population than their early day equivalents. Spatial variation between the cheese core and rind was also noted in that cheese rinds were found to initially have a more diverse microbial population but thereafter the opposite was the case. Interestingly, the genera Thermus, Pseudoalteromonas and Bifidobacterium, not routinely associated with a Continental-type cheese produced from pasteurised milk were detected. The significance, if any, of the presence of these genera will require further attention. Ultimately, the use of high throughput sequencing has facilitated a novel and detailed analysis of the temporal and spatial distribution of microbes in this complex cheese system and established that the period during a production cycle at which a cheese is manufactured can influence its microbial composition.This work was funded by the Department of Agriculture, Food and the Marine under the Food Institutional Research Measure through the ‘Cheeseboard 2015’ project. Daniel J. O’Sullivan is in receipt of a Teagasc Walsh Fellowship, Grant Number: 201220

Impact of health labels on flavor perception and emotional profiling : a consumer study on cheese

The global increase of cardiovascular diseases is linked to the shift towards unbalanced diets with increasing salt and fat intake. This has led to a growing consumers’ interest in more balanced food products, which explains the growing number of health-related claims on food products (e.g., “low in salt” or “light”). Based on a within-subjects design, consumers (n = 129) evaluated the same cheese product with different labels. Participants rated liking, saltiness and fat flavor intensity before and after consuming four labeled cheeses. Even though the cheese products were identical, inclusion of health labels influenced consumer perceptions. Cheese with a “light” label had a lower overall expected and perceived liking compared to regular cheese. Although cheese with a “salt reduced” label had a lower expected liking compared to regular cheese, no lower liking was found when consumers actually consumed the labeled cheese. All labels also influenced the perceived intensities of the attributes related to these labels, e.g., for example salt intensity for reduced salt label. While emotional profiles of the labeled cheeses differed before tasting, little differences were found when actual tasting these cheeses. In conclusion, this study shows that health-related labels might influence the perceived flavor and emotional profiles of cheese products

Swiss-Cheese operad and Drinfeld center

We build a model in groupoids for the Swiss-Cheese operad, based on parenthesized permutations and braids, and we relate algebras over this model to the classical description of algebras over the homology of the Swiss-Cheese operad. We extend our model to a rational model for the Swiss-Cheese operad, and we compare it to the model that we would get if the operad Swiss-Cheese were formal.Comment: 27 pages. v5: Minor corrections. To appear in Israel J. Mat

Cheese: Food Perception and Food Choice

In light of the increasing interest in the economic and socio-political impact of the ‘traditional food’ trend, it is essential to understand the determinant factors that lead to traditional consumer choices. The standardization of sensory quality evaluation methods marks the pressing need for food product certification, particularly foods with specific sensory characteristics, such as those with a Protected Designation of Origin (PDO). Consumer perception of particular foods, especially for foods that are culturally and socially contingent, such as cheese, must be understood as both a psychophysical reflex and a learned social practice. Consumers create their own perceptions based on the overall intrinsic or extrinsic cheese characteristics, mainly sensory characteristics that reflect others' attributes. These characteristics are normally linked to the specific cheese manufacture process. Some patents propose the use of adapted cheesemaking equipment (EP1982582A2), suitable for the manufacture of small-scale cheeses, such as some PDO cheese. Thus, sensory evaluation of any kind of cheese is based, in the initial phase, on knowledge of the sensory methods for cheese evaluation and, in a second phase, on the familiarity of the cheese characteristics and verbalization of desirable and undesirable attributes. This paper presents a case study based on the traditional food product, Évora cheese, assembled with PDO cheeses, whose sensory and physicochemical quality attributes are essential in order to obtain this designation and ensure the genuine properties that characterize them, as well as ascertaining exactly how they are perceived and further accepted by the consumer

Aspects of proteolysis in cheese : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Food Technology at Massey University

The purpose of the present study was to elaborate methods for the detailed examination of proteolysis pathways in cheese (reviewed in Chapter 1) and to demonstrate their usefulness. Many techniques, including solvent fractionation, chromatographic separation and electrophoresis have been used previously and were revisited in this study. Gel electrophoresis can be a powerful technique and was examined in detail. The methods investigated were: 1) a slab gel system using the apparatus of the E-C Apparatus Corporation and a polyacrylamide gel in a Tris-EDTA-borate buffer at alkaline pH and containing urea; 2) a mini-slab gel system using the Bio-Rad mini-Protean II apparatus, a polyacrylamide stacking and resolving gel with a discontinuous (Tris-chloride/Tris-EDTA-borate) buffer system that contained urea; 3) a mini-slab gel system using the Bio-Rad mini-Protean II apparatus, a polyacrylamide stacking and resolving gel and acetic acid-ammonium acetate buffers at acidic pH that contained urea; 4) a mini-slab gel system using the Bio-Rad mini-Protean II apparatus, a polyacrylamide gel with a stacking and resolving gel in Tris-HCl buffers containing sodium dodecyl sulphate (SDS) and a Tris-chloride-glycine electrode buffer. The mini-slab alkaline urea polyacrylamide gel electrophoresis (PAGE) method was considered to be the most suitable for monitoring the loss of intact casein during cheese ripening. However, SDS-PAGE gave good resolution of para-κ-casein, β-lactoglobulin and α-lactalbumin and it could therefore be used for the analysis of cheese in which whey proteins have been incorporated or for monitoring the breakdown of para-κ-casein (Chapter 4) in cheese. Two-dimensional PAGE revealed the presence of more bands than were visible using any single method of electrophoresis. Traces of protein were found to lie beneath the α31-casein band and this explained why, even after considerable proteolysis, some α31-casein appeared to remain. Storing cheese samples in such a way that there is a minimum of further change was examined using several different storage methods and temperatures, including storage as: freeze-dried powder at 4°C in the dark, frozen at -9, -16, -35,-75 and -100°C, and dissolved in 6 M urea solution and stored at 4 and -16°C. The trial ran for 6 months and involved the multiple sampling and detailed analysis of three Cheddar cheeses by reversed phase fast protein liquid chromatography (RP-FPLC) for the water-soluble fraction (WSF) and alkaline urea-PAGE for the protein fraction. None of the methods used to store the cheese samples was completely satisfactory. Cheese stored at temperatures of -9 and -16°C was unstable, with proteolysis discernible after 66 days. Storage of cheese samples at these temperatures is, therefore, not recommended. Cheese stored at temperatures of -35, -75 and -100°C was unstable after 94 days, although the samples stored at -100°C were more stable. This lack of stability probably arose during thawing as well as during storage of the frozen cheese samples. Storage of freeze-dried samples at4°C in the dark was equivalent to storing the frozen cheese at -100°C. Storage of samples in alkaline urea sample buffer was better at -16°C than at 4° but should be for no longer than 1 month. An indication of the differences to be expected within the normal range of Cheddar cheese was determined using three very similar Cheddar cheeses ripened at5 and 13°C (Chapter 3, part II). Cheeses ripened at 5°C for 6 months were similar to those ripened at 13°C for 2 months and the proteolytic pathways appeared to the same at both temperatures. The proteolytic pathways in Cheddar and Mozzarella cheeses, manufactured according to standard protocols, ripened at 13°C and sampled at regular intervals over a six month period were examined using a variety of techniques: total nitrogen (TN), non- protein nitrogen (NPN), water-soluble nitrogen (WSN), alkaline urea-PAGE, low molecular weight (LMW) SDS-PAGE, RP-FPLC and size exclusion high performance liquid chromatography (SE-HPLC). The TN and NPN analyses were done at the time of sampling whereas the other assays were done on samples that had been stored at <-75°C so that they could be analysed simultaneously. The increase in WSN and NPN was greater in Cheddar cheese than in Mozzarella cheese and reflected the greater microbial enzyme activity in this cheese type. Alkaline urea-PAGE revealed that there was more α31-casein hydrolysis (with the formation of α31-casein-I) in Cheddar cheese than in Mozzarella cheese, indicating that rennet activity was greater in Cheddar cheese. The presence of peptides believed to be β-I- (β-casein fl-189/192) and β-II-casein (β-casein fl-165) indicated that rennet may have hydrolysed β-casein. The amount of β-casein hydrolysis (and γ-casein formation) was greater in Mozzarella cheese, reflecting the greater plasmin activity in this cheese type. Both LMW SDS-PAGE and SE-HPLC of the whole cheese provided little additional information. Examination of the WSF of each cheese by PAGE analysis showed that many of the larger peptides may have been present in both cheese types. The different concentrations of these peptides in each cheese type were consistent with different rennet and plasmin activities and suggested that they may have been products of these enzymes. RP-FPLC and SE-HPLC analysis of the WSF of Cheddar cheese revealed that, although the larger peptides continued to accumulate during ripening, there was also a large increase in the amount of small peptides and amino acids in the cheese. In the Mozzarella cheese, the larger peptides accumulated and there was little evidence of their further hydrolysis to small peptides and amino acids. The present studies indicate that SE-HPLC using a Toyo-Soda SW 2000 column and a 36% acetonitrile/0.1 % trifluoroacetic acid solvent system is a promising new technique that may be useful in determining cheese type and maturity and in relating changes in the molecular weight distribution of the peptides to changes in the textural, functional and flavour characteristics of cheese. It was concluded that the results are consistent with the concept that differences in the manufacture of Cheddar and Mozzarella cheeses result in the formation of two cheeses, each with different amounts of similar enzymes (rennet, plasmin, and the enzymes of the starter and non-starter lactic acid bacteria), and that these differences in enzyme concentration, combined with the modifying effect of pH, temperature, moisture content and S/M, result in different enzyme activities and patterns of proteolysis in the two types of cheese and these,in turn, result in cheeses with different functional properties

Nucleic acid-based approaches to investigate microbial-related cheese quality defects

peer-reviewedThe microbial profile of cheese is a primary determinant of cheese quality. Microorganisms can contribute to aroma and taste defects, form biogenic amines, cause gas and secondary fermentation defects, and can contribute to cheese pinking and mineral deposition issues. These defects may be as a result of seasonality and the variability in the composition of the milk supplied, variations in cheese processing parameters, as well as the nature and number of the non-starter microorganisms which come from the milk or other environmental sources. Such defects can be responsible for production and product recall costs and thus represent a significant economic burden for the dairy industry worldwide. Traditional non-molecular approaches are often considered biased and have inherently slow turnaround times. Molecular techniques can provide early and rapid detection of defects that result from the presence of specific spoilage microbes and, ultimately, assist in enhancing cheese quality and reducing costs. Here we review the DNA-based methods that are available to detect/quantify spoilage bacteria, and relevant metabolic pathways in cheeses and, in the process, highlight how these strategies can be employed to improve cheese quality and reduce the associated economic burden on cheese processors.This work was funded by the Department of Agriculture, Food and the Marine under the Food Institutional Research Measure. Daniel J. O’Sullivan is in receipt of a Teagasc Walsh Fellowship, Grant Number:2012205

Milk quality and cheese diversification

peer-reviewedAbolition of EU milk quotas in 2015 is projected to result in a 2.75 billion litre increase in Irish milk production by 2020. Although cheese offers vital market opportunities for this increased milk production, traditional cheese markets such as Cheddar, are predicted to grow more slowly than for other semi-soft and semi-hard cheese types. Innovation is now focused on achieving greater diversity in cheese types manufactured on Irish commercial plants and on development of new products with specific properties for target markets. This innovation is best illustrated by the current Teagasc – Irish Dairy Board collaboration. This review considers the relative influence of milk quality on diversification of the portfolio of cheeses manufactured from a seasonally-produced Irish milk supply with particular reference to milk microbial profile and to milk enzyme complement for the manufacture and ripening of non-Cheddar cheese varieties

Real deal or no deal? A comparative analysis of raw milk cheese regulation in Australia and France

Australia’s regulatory framework has resulted in the standardisation of cheese production based on pasteurisation. Up until early 2015, regulations effectively prohibited raw milk cheese-making in Australia and thus stifled artisanal on-farm production. Although the introduction of Food Standards Australia New Zealand Standard 4.2.4 has allowed the production of certain hard, low-moisture raw milk cheeses, the new standard is rigid and does not encourage new entrants into the emerging raw milk cheese consumer market. This article compares the Australian system with the French raw milk cheese regulation and production system, and argues that its approach in encouraging and supporting small farmhouse artisanal traditional raw milk cheese is beneficial to both producer and consumer, and has not resulted in any significant health risks. The Australian approach amounts to a missed opportunity to encourage the emergence of a value-added industry with local and export potential, and is at odds with important movements in food policy, such as recognition of the value of localism and terroir