Influence of storage,brine concentration and in‐container heat treatment on the stability of white brined Nabulsi cheese

Microbial levels were significantly (P < 0.05) affected by the temperature‐time treatments used during in‐container heat treatment of the curd, brine concentration and storage duration. A heat treatment of 115 °C × 2 min, in the absence of NaCl, was sufficient to eliminate Mesophilic micro‐organisms, Coliforms, Staphylococcus aureus and Yeast and Moulds for the duration of 1 year of storage. Sensory scores for colour, appearance and texture increased significantly (P < 0.05) with the increase in the NaCl in brine concentration regardless of the temperature‐time treatment.     

Microbiological quality of shredded Cheddar cheese packaged in modified atmospheres

The microbiological quality of shredded Cheddar cheese packaged in different modified atmospheres with and without oxygen scavengers included in the packaging film was studied with the aim of determining how modified air packaging would affect the mould species present on shredded Cheddar cheese. The film with oxygen scavengers was more effective than the control film against mould growth, whereas the 73% CO₂/27% N₂ atmosphere resulted in the cheese with the best microbiological qualities. The three modified atmospheres and the packaging film influenced the mycoflora of shredded Cheddar cheese as the mould species isolated initially differed, from those isolated at 16 weeks in the six treatments. This study demonstrated that O₂ scavengers were effective in controlling the growth of moulds on shredded Cheddar cheese.     

Perceptions of Brazilian consumers regarding white mould surface‐ripened cheese using free word association

The aim of this study was to understand the perceptions and/or choices of Brazilian consumers regarding white mould surface‐ripened cheeses using the free word association method (FWAM). A total of 350 words, including ‘high quality’, ‘nice’, ‘beautiful’, ‘ammonia/milk aroma’, ‘soft and creamy texture’, ‘mild flavour’ and ‘velvety appearance’, were used by 408 volunteers. These words were influenced by the cultural diversity of foods. The FWAM can help to develop strategies to strengthen the frequent and occasional consumption of white mould surface‐ripened cheese, and also to encourage its consumption by those who currently do not purchase this product.     

Personality traits,knowledge, and consumer acceptance of genetically modified plant and animal products

Several studies have investigated the associations between personality traits and consumer behavior, but little attention has been paid to the role of personality traits in the acceptance of genetically modified (GM) food products or knowledge concerning the application of GM technologies. We used a large Norwegian survey to investigate the associations between personality traits, knowledge about GM use in agriculture, attitudes, and willingness to pay (WTP) to avoid GM foods. Using a random effect interval regression model, we found premiums between 19% and 23% to avoid GM soybean oil, GM-fed salmon, and GM salmon. Neuroticism was associated with increased acceptance of GM soybean oil. Conscientiousness was associated with increased acceptance of GM-fed and GM salmon, and agreeableness was associated with increased aversion against these products. Conscientiousness and agreeableness were also associated with knowledge. Agreeable respondents were less likely to think that genetic modification was applied in Norwegian agriculture, and conscientious respondents were more likely to wrongly think so. Attitudes towards naturalness of foods were strongly correlated with increased WTP to avoid GM foods. Current policy restrictions concerning the use of GM technologies are likely to affect the perceived safety of GM foods. Information and more liberal regulations may change attitudes towards GM foods and reduce the resistance against GM technologies over time.     

Polyphosphates as inhibitors of surface mould growth on hard cheese during ripening

A novel treatment using polyphosphates to protect cheeses against superficial mould growth was assayed. The treatments were: control commercial paint with natamycin (I), commercial paint based on polyvinyl–water (II), immersion in a saturated solution of polyphosphate (III), immersion and commercial paint (IV), commercial paint of polyphosphate solutions (V) and immersion and commercial paint of a saturated solution of polyphosphates (VI). The cheeses were ripened for 6 months. Superficial mould growth was inhibited in groups IV and VI when compared to cheeses from the control group (I). Statistical sensory analysis made between cheeses from groups IV and I (control) showed no significant differences.     

A probiotic soy-based innovative product as an alternative to petit-suisse cheese

The present study aimed to develop a probiotic soy-based product similar to petit-suisse cheese and to evaluate its perspectives regarding potential for consumer health benefits, sensory acceptability, and instrumental texture during storage. Three different trials were studied: MP (milk-based petit-suisse – control); MSP (mixed product with milk cream and soy); SP (soymilk-based product). The formulations were produced with an ABT culture, containing Lactobacillus acidophilus La-5, Bifidobacterium animalis Bb-12, and the starter Streptococcus thermophilus and stored at 4 °C for up to 28 days. Bb-12 viability remained always above 8 log cfu g⁻¹ for all trials, whereas viability of La-5 was satisfactory at the end of storage for MP (7.56 log cfu g⁻¹) and MSP (6.49 log cfu g⁻¹), but only up to 21 days (6.84 log cfu g⁻¹) for SP. The pH remained stable and was lower for MSP (p < 0.05), whereas instrumental hardness and gumminess increased in soy-based products (MSP and SP) and decreased in the control (MP). SP had the highest sensory score means (6.4) on day 21, being sensorially attractive to provide consumers with a functional food without dairy ingredients and with high viability of the probiotic microorganisms.     

The use of buttermilk as a raw material for cheese production

Buttermilk is dairy by‐product of butter production. The study aimed to analyse the quality properties of commercial buttermilk and its usefulness as a raw material for Quark cheese production. Within the study, 6 kinds of buttermilk were tested and used for cheese production. Evaluation of cheese quality included physico‐chemical, rheological and sensory analyses. Buttermilk properties were varied and corresponded with the diversification of cheese characteristics. Production yield was 17.2–22.7%, water content 68.1–75.8% and pH 4.09–4.43. The texture was diversified; however, all samples had good sensory quality. The research has shown that buttermilk is a good raw material for cheese production.     

Physicochemical,biochemical, microbiological and safety aspects of Pico cheese: Assessment throughout maturation and on the final product

Pico cheese is a traditional variety manufactured on the eponymous Azorean Island (Portugal). In total, 153 cheeses were analysed. The average total solids (TS) content by the end of maturation was 63.3 ± 0.3 g/100 g, A_w 0.943–0.966, salt‐in‐moisture 2.12–4.17 g/100 g and pH 4.89–5.11 ± 0.02. Proteolysis was similar to that of other Iberian raw milk cheeses, but the free fatty acid content was generally higher. Lactococci were the predominant bacteria. Coagulase‐positive staphylococci constituted the most severe hygiene problem. Positive correlations were found between maturation time and TS, titratable acidity, A_w, proteolysis indices and Enterobacteriaceae and coagulase‐positive staphylococcus viable numbers.     

Personality traits and consumer acceptance of controversial food technology: A cross-country investigation of genetically modified animal products

Recent breakthroughs in biotechnology have expanded the range of applications in animal agriculture. Acceptance of food products from these animals is expected to be controversial and requires a thorough understanding of consumer preferences and drivers of acceptance. This paper explores the role of personality, measured via the Big Six personality traits (Agency, Agreeableness, Openness, Neuroticism, Extraversion and Conscientiousness), on consumer acceptance of a genetically modified pork product in the US (N = 945), China (N = 945) and Italy (N = 954). The effect of personality is most evident in US consumers with five out of six personality traits explaining preferences for genetically modified pork. Openness was the only trait that consistently explained consumer acceptance in our three countries and conscientiousness was found to be a good predictor in Western cultures. Our results reinforce the need to use psychological characteristics of consumers to understand controversial food acceptance and highlight the differential impact of personality across cultures.     

Consumer attitude towards sodium reduction in meat products and acceptability of fermented sausages with reduced sodium content

Lowering salt content in meat products is possible from a technological and sensorial point of view, although little information is available about the consumers' attitude and acceptance of these products. Attitude towards low salt meat products, following the Theory of Planned Behaviour (TPB) proposed by Ajzen, was evaluated by 392 consumers. Acceptability of small calibre fermented sausages with 50% molar substitution of NaCl by six different mixtures of KCl (0-50%) and K-lactate (0-50%) and the control (22g NaCl/kg) was determined by 98 consumers. The preference of the previous best two treatments was compared to the batch control by 279 consumers. In general consumers had a positive attitude towards low salt meat products, being higher for women than for men. Women showed stronger ideas and higher Perceived Control on the Behaviour towards reduced sodium meat products than men. Smokers showed lower intense beliefs than non-smokers. Consumers with a basic level of education were more affected by what other people important for them thought they should do. The final model obtained using the Theory of Planned Behaviour showed a good predictive capacity (R(2)=0.60) and a good internal consistency. Regarding the acceptability study, batches with substitution levels of 50% and 40% by K-lactate, showed lower overall acceptance than the control batch. Significant differences in acceptability were found regarding the gender and place of residence of the consumers. The preference study showed no differences between the batch control and batches with 50% KCl and 40% KCl + 10% of K-lactate substitution levels. According to these results and from a sensorial point of view, it is possible to reduce NaCl content in small calibre fermented sausages by 50% and obtain a product acceptable for consumers.     

Spatial distribution of light-induced lipid oxidation in semi-hard yellow cheese as detected by confocal microscopy

The migration of oxidative damage in semi-hard yellow cheese resulting from surface exposure to 436 nm monochromatic light with an intensity of 2.5 × 10¹⁷ quanta min⁻¹ cm⁻² for 0, 5, 10, and 15 min was followed by confocal laser scanning microscopy using labelling with the lipophilic fluorescence ratio probe C₁₁-Bodipy (581/591). From 5 × 5 × 5 mm cubes of cheese exposed to light on one plane 35 μm was sliced off and fluorescence of oxidised and non-oxidised probe recorded simultaneously on the surface of the slice reaching 250 μm inwards from the exposed surface. From the emission of the fluorescence ratio probe light-induced lipid oxidation could be followed with time of exposure to light. The penetration of light inwards in the cheese with time expressed as quanta cm⁻², as calculated from light transmittance at 436 nm determined spectrophotometrically for cheese slices of up to 300 μm thickness, together with light intensity as determined by actinometry, could alone account for the inwards migration of oxidation. Diffusion of radicals seems of less importance for spatial dispersion of light-induced oxidation in semi-hard cheese.     

Evaluation of a chitosan-based edible film as carrier of natamycin to improve the storability of Saloio cheese

The purpose of this study was to evaluate the effects of the application of chitosan coating containing natamycin on the physicochemical and microbial properties of semi-hard cheese. Three cheese groups were prepared: samples without coating, samples coated with chitosan and with chitosan containing 0.50 mg mL⁻¹ of natamycin, whose minimum inhibitory concentration was previously determinated on cheese surface. Microbiological analyses showed that natamycin coated samples presented a decrease on moulds/yeasts of 1.1 log (CFU g⁻¹) compared to control after 27 days of storage. Addition of natamycin also affected O₂ and CO₂ permeability, increasing from 7.12 to 7.68 × 10⁻¹⁵ g·(Pa s m)⁻¹, and from 10.69 to 64.58 × 10⁻¹⁴ g·(Pa s m)⁻¹, respectively. The diffusion coefficient values of natamycin from the film to phosphate buffered saline solution and to the cheese were 3.60 × 10⁻¹⁰ and 1.29 × 10⁻¹² cm² s⁻¹, respectively. This study demonstrated that chitosan-based coating/films can be used as release system containing natamycin to create an additional hurdle for moulds/yeasts in cheese thus contributing to extend its shelf-life.     

Quality and yield of Ricotta cheese as affected by milk fat content and coagulant type

Milk processing conditions can exert a large influence on the quality of acid‐coagulated cheeses. Herein, we evaluated the influence of milk fat content and coagulant type on Ricotta yield and physical, chemical and sensory properties. Fat‐free Ricotta was hard and whiter than reduced‐fat or full‐fat Ricotta. Ricotta produced from low‐fat and whole milk showed no differences in acceptability, indicating that fat content could be substantially reduced without impairing quality. Milk coagulation by citric acid decreased Ricotta moisture, firmness and yield, whereas calcium chloride produced a white Ricotta with desired firmness and high consumer acceptability.     

The use of non-hypothetical experimental markets for measuring the acceptance of genetically modified foods

The findings from a study measuring consumer acceptance of genetically modified (GM) foods are presented. The empirical data were collected in an experimental market, an approach used extensively in experimental economics for measuring the monetary value of goods. The approach has several advantages over standard approaches used in sensory and marketing research (e.g., surveys and focus groups) because of its non-hypothetical nature and the realism introduced by using real goods, real money, and market discipline. In each of three US locations, we elicited the monetary compensation consumers required to consume a GM food. Providing positive information about the benefits of GM food production, in some cases, reduced the level of monetary compensation demanded to consume the GM food.     

北京市城区居民的转基因食品知识、态度、行为及影响因素分析

为了解北京市居民对转基因食品的知识、态度和行为的现状及影响因素。抽取北京市居民中901人，调查转基因食品生物技术的知信行水平。转基因食品是生物技术的知晓率为72．7％，深入了解的49．3％，随化程度增高呈上升趋势。对转基因食品持乐观态度的占63．1％，持悲观态度(有害或害大于利)的占6．1％，乐观随化程度增高呈上升趋势，随年龄增高呈下降趋势；61．9％的调查认为转基因食品将走向大众(积极)，30岁以下及乐观的人群态度更为积极。持乐观、积极态度购买转基因食品的比率较高，为41．8％，而持悲观态度的为18．7％，差异有显性；购买转基因食品人群比例随年龄升高呈下降趋势，与化程度、性别没有关系；调整的价格对促进转基因食品购买有一定影响。北京市居民对转基因食品的知信行水平较高，态度影响购买行为，转基因食品的价格对购买有一定影响。     

Evaluation of the ability of Yarrowia lipolytica to impart strain-dependent characteristics to cheese when used as a ripening adjunct

Four Yarrowia lipolytica strains were tested as cheese-ripening adjuncts with milk culture in cheese production to evaluate their effects on the microbiological and biochemical features of the cheeses. The Y. lipolytica strains were able to overcome the other naturally occurring yeasts and were compatible with lactic acid bacteria (LAB). Fourier transform infrared (FTIR) profiles and analysis of free fatty acids (FFAs) released during ripening showed that the strains induced a marked lipolysis and gave rise to different FFAs accumulation over time with respect to the control. Strain-dependent protein breakdown patterns were identified and these biochemical differences resulted in different cheese organoleptic characteristics.     

Comparison of molecular and metabolomic methods as characterization tools of Debaryomyces hansenii cheese isolates

Debaryomyces hansenii is one of the yeast species most frequently isolated from cheese and salty foods, however little is known about the phenotypic and molecular variability of its strains. In order to explore the possibilities of a large study on its biodiversity, some D. hansenii strains were selectively isolated from pecorino cheese sampled in ten different Italian regions. All isolates were identified as D. hansenii on the basis of conventional and molecular taxonomic analysis. The D1/D2 domain sequences of the 26S-rDNA did not show any variation, confirming the extreme homogeneity of this species. PCR-duplex-RAPD banding patterns analyzed with PCoA showed interesting clustering related to the geographic areas of isolation, although some overlapping between strains derived from different districts could be observed. A FTIR (Fourier Transform Infrared Spectroscopy) metabolomic fingerprint produced groupings weakly related to those observed with RAPD and less associated with the isolation locales. The discriminatory power of metabolomic fingerprint was able to discriminate strains otherwise considered identical. This preliminary study showed that, in spite of the homogeneity at the 26S-rDNA level, the D. hansenii strains exhibit high molecular and metabolomic variability somehow linked to the places of isolation. Further studies will be necessary to better investigate on the link between terroir and strain variability, as well as on the relation between genotypic and metabolomic fingerprints.     

Growth control of genetically modified cells using an antibody/c-Kit chimera

Gene therapy has been regarded as an innovative potential treatment against serious congenital diseases. However, applications of gene therapy remain limited, partly because its clinical success depends on therapeutic gene-transduced cells acquiring a proliferative advantage. To address this problem, we have developed the antigen-mediated genetically modified cell amplification (AMEGA) system, which uses chimeric receptors to enable the selective proliferation of gene-transduced cells. In this report, we describe mimicry of c-Kit signaling and its application to the AMEGA system. We created an antibody/c-Kit chimera in which the extracellular domain of c-Kit is replaced with an anti-fluorescein single-chain Fv antibody fragment and the extracellular D2 domain of the erythropoietin receptor. A genetically modified mouse pro-B cell line carrying this chimera showed selective expansion in the presence of fluorescein-conjugated BSA (BSA-FL) as a growth inducer. By further engineering the transmembrane domain of the chimera to reduce interchain interaction we attained stricter ligand-dependency. Since c-Kit is an important molecule in the expansion of hematopoietic stem cells (HSCs), this antibody/c-Kit chimera could be a promising tool for gene therapy targeting HSCs.     

The compositional properties,proteolytic–lipolytic maturation parameters and volatile compositions of commercial enzyme‐modified cheeses with different cheese flavours

Eight different commercial enzyme‐modified cheeses (EMCs) were analysed, and the distinctive/common features of the products and production methods were investigated. Results showed that the total free fatty acid contents of EMC samples were 10 to 100 times higher than the values reported for the related cheese varieties. A total of 37 volatile compounds were identified, and acids were found as the most dominant group in all EMC samples. While furan compounds and 2‐acetylpyrrole were most intensively detected in the goat cheese EMC, methyl ketones were found in the highest amounts in Blue cheese EMC.