Composition, proteolysis, lipolysis, volatile compound profile and sensory characteristics of ripened white cheeses manufactured in different geographical regions of Turkey

Probiotic Potential and Application of Indigenous Non-Starter Lactic Acid Bacteria in Ripened Short-Aged Cheese

There are massive sources of lactic acid bacteria (LAB) in traditional dairy products. Some of these indigenous strains could be novel probiotics with applications in human health and supply the growing needs of the probiotic industry. In this work, were analyzed the probiotic and technological properties of three Lactobacilli strains isolated from traditional Brazilian cheeses. In vitro tests showed that the three strains are safe and have probiotic features. They presented antimicrobial activity against pathogenic bacteria, auto-aggregation values around 60%, high biofilm formation properties, and a survivor of more than 65% to simulated acid conditions and more than 100% to bile salts. The three strains were used as adjunct cultures separately in a pilot-scale production of Prato cheese. After 45 days of ripening, the lactobacilli counts in the cheeses were close to 8 Log CFU/g, and was observed a reduction in the lactococci counts (around -3 Log CFU/g) in a strain-dependent manner. Cheese primary and secondary proteolysis were unaffected by the probiotic candidates during the ripening, and the strains showed no lipolytic effect, as no changes in the fatty acid profile of cheeses were observed. Thus, our findings suggest that the three strains evaluated have probiotic properties and have potential as adjunct non-starter lactic acid bacteria (NSLAB) to improve the quality and functionality of short-aged cheeses.

Bioactive potential of ripened white cheeses manufactured in different geographical regions of Turkey

This study investigated the potential bioactive properties of white cheeses produced in different regions of Turkey, including their potential antioxidant, antihypertensive, antidiabetic, antimicrobial, and anticancer activities. The cheese samples were analyzed both before and after in vitro digestion. The study found that all cheese samples exhibited significant angiotensin-converting enzyme inhibition activity both before (45.5%-70.1% for 0.03 g cheese/mL) and after in vitro digestion (25.5%-63.5% for 0.0167 g cheese/mL), whereas α-amylase inhibition activity was present in all samples (in the range of 5.1%-50.0% for 3.0 × 10-5  g cheese/mL) but disappeared after digestion, and α-glucosidase inhibition activity was only detected after in vitro digestion (from 20.5% to 60.4% for 5.6 × 10-5  g cheese/mL), indicating potential antidiabetic properties. However, antimicrobial and anticancer activities were not observed in any of the samples. The results also suggest that the bioactivity potential of white cheese may vary depending on the region of production, as cheeses from the Marmara region exhibited high α-glucosidase inhibition activity after digestion. In conclusion, while white cheese is a valuable addition to the diet due to its high nutritional value and potential health benefits. This study revealed the bioactive potential of ripened white cheese and in vivo investigations of the cheese components would better show their possible benefits. PRACTICAL APPLICATION: Although the bioactivity potentials varied among the ripened white cheese samples produced in different regions of Turkey, a consistent trend was observed in terms of their presence or absence. Our research revealed that all ripened cheese samples demonstrated significant potential antioxidant and antihypertensive activities, as well as potential antidiabetic properties. Moreover, it can be interpreted that ripened white cheese has the potential to reduce the digestion of carbohydrates when consumed with carbohydrate-rich foods. Although the present results provide limited practical findings directly applicable to the industry, if the data and information obtained from this study are further explored and further studies delving into specific mechanisms of bioactive components could emerge.

The characterization of the non-starter lactic acid bacteria and yeast microbiota and the chemical and aromatic properties of traditionally produced Turkish White Cheese

Turkish White Cheese is a brined (or pickled) cheese with a salty, acidic flavor and a soft or semi-hard texture. It is the most produced and consumed type of cheese in Turkey. The purpose of this study was to determine the non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese and analyze the chemical properties and the aroma profile of the cheese. The results of the study identified 27 distinct strains belonging to 14 the non-starter lactic acid bacteria species and 49 different strains belonging to 11 yeast species. Lactobacillus plantarum was found to be the dominant species among the lactic acid bacteria, while Candida zeylanoides was the dominant yeast species in the White Cheese samples. In addition, Kluyveromyces lactis and Debaryomyces hansenii were prominent yeast species in cheese samples. Turkish White Cheese samples had different aromatic properties. The study is highly significant as it anaylzed both non-starter lactic acid bacteria and yeast microbiota of traditionally produced Turkish White Cheese through molecular methods. It also determined and analyzed a number of chemical and aromatic properties of White Cheese.

Analysis of the effect of Tenebrio Molitor rennet on the flavor formation of Cheddar cheese during ripening based on gas chromatography-ion mobility spectrometry (GC-IMS)

This study aimed to evaluate the potential application of Tenebrio Molitor rennet (TMR) in Cheddar cheese production, and to use gas chromatography-ion mobility spectrometry (GC-IMS) to monitor flavor compounds and fingerprints of cheese during ripening. The results indicated that Cheddar cheese prepared from TMR (T_F) has fat content significantly lower than that of commercial rennet (C_F) (p < 0.05). However, the results of the sensory evaluation showed that there were no statistically significant differences between the two kinds of cheese (p > 0.05). Both cheeses were rich in free amino acids and free fatty acids. Compared to the C_F cheese, gamma-aminobutyric acid and Ornithine contents of the T_F cheese reached 187 and 749 mg/kg, respectively, during 120 days of ripening. Moreover, GC-IMS provided information on the characteristics of 40 flavor substances (monomers and dimers) in the T_F cheese during ripening. Only 30 flavor substances were identified in the C_F cheese. The fingerprint of the two kinds of cheese during ripening can be established by GC-IMS and principal component analysis based on the identified flavor compounds. Therefore, TMR has potential application in Cheddar cheese production. GC-IMS might be applied for the quick, accurate and comprehensive monitoring of cheese flavor during ripening.

Characterisation of the Aroma Profile and Dynamic Changes in the Flavour of Stinky Tofu during Storage

Stinky tofu is a traditional Chinese food with wide consumption in China. Nevertheless, the dynamic changes in the flavour of stinky tofu during storage have yet to be investigated. In this study, the flavour changes of stinky tofu over six different storage periods were comprehensively analysed through sensory, electronic nose and gas chromatography-mass spectrometry (GC-MS) analyses. The results of the sensory and electronic nose analyses confirmed the changes in the flavour of stinky tofu across different storage periods. In the GC-MS analysis, 60 volatile compounds were detected during storage, and the odour activity values indicated that 29 of these 60 compounds significantly contributed to the aroma profile. During storage, the alcohol concentration of the stinky tofu gradually decreased while the acid and ester concentrations increased. According to a partial least squares analysis, 2-phenylethyl acetate, 2-phenylethyl propanoate, p-cresol, and phenylethyl alcohol, which were detected after 10 days of storage, promoting the release of an overripe apple-like odour from the stinky tofu. Findings regarding the flavour changes and characteristics of stinky tofu during different storage periods can provide a potential reference for recognising the quality of these products.

Effects of milk types used in Antep cheese production on some cheese organoleptic quality parameters and brine composition during 5-month ripening

Antep cheese is a local Turkish cheese characterized by scalding during production and ripened in brine. In this study, Antep cheeses were produced using mixtures of different milk types (cow, sheep, and goat milk) and ripened for 5 months. The composition, proteolytic ripening extension index (REI), free fatty acid (FFA) content, and volatile compounds of the cheeses and the variation of the brines were analyzed for the 5-month ripening period. Low proteolytic activity in cheese during ripening caused the cheeses to have low REI values (3.92%-7.57%), although it was observed that some parts of the water-soluble nitrogen fractions diffused into the brine, causing a lower REI. As a result of lipolysis during ripening, total FFA (TFFA) concentrations in all cheeses were increased, whereas the highest increases were detected in the concentrations of short-chain FFAs. The highest FFA concentrations were determined in cheese produced using goat milk, and the volatile FFA ratio in TFFA exceeded 10% in the third month of ripening. Although it was observed that the milk types used in the production had significant effects on the change of volatile compounds of the produced cheeses and their brines, the impact of the ripening time was more important. PRACTICAL APPLICATION: This study investigated Antep cheese made with different milk types. Volatile compounds and soluble nitrogen fractions were transferred to the brine by diffusion during ripening. The volatile profile of the cheese varied with milk type, but ripening time was the primary factor influencing volatile compounds. This suggests that the targeted organoleptic properties of the cheese are determined by ripening time and conditions. Additionally, changes in the brine's composition during the ripening process provide insight into how to manage the brine as waste.

Changes in Physicochemical and Microbiological Properties, Fatty Acid and Volatile Compound Profiles of Apuseni Cheese during Ripening

The evolution during ripening on the quality of Apuseni cheese was studied in this research. The cheese samples were controlled and evaluated periodically (at 4 months) during 16 months of storage (at 2–8 °C) for physicochemical parameters (pH, moisture, fat, fat in dry matter, total protein, ash, NaCl), microbiological (total combined yeasts and molds count (TYMC), total viable count (TVC), Escherichia coli, Staphylococcusaureus, Salmonella, lactic acid bacteria (LAB)), fatty acids (FA) and volatile compounds. For better control of the quality of the cheese, the storage space was evaluated for TYMC and TVC. The ripening period showed improved effects on the quality of the cheese, showing lower values for moisture and pH and an increase in macronutrients. Both the cheese samples and the storage space were kept within the allowed microbiological limits. Lipids are predominant, the predominant FAs being saturated fatty acids (SFAs), which decrease, while monounsaturated fatty acids (MUFAs) increase. During ripening, the microbiological and chemical changes result in the development of flavor. Major volatile compounds such as 2-heptanone show accumulations, while acetophenone, limonene, or thymol show a decrease. In conclusion, Apuseni ripening cheese clearly involves a complex series of transformations, leading to a ripening cheese with improved nutritional and aromatic characteristics.

Physico-Chemical, Sensory and Texture Properties of an Aged Mexican Manchego-Style Cheese Produced from Hair Sheep Milk

The objective of this study was to evaluate the physicochemical and texture changes of the Manchego-style cheese produced from hair sheep (Pelibuey) throughout 180 days of ripening, as well as consumer's acceptance. Cheese pH was constant from 1 to 180 days of ripening. Moisture, water activity, fat, elasticity and hardness decreased from day 1 to day 180, while protein, trichloroacetic acid-soluble N and free amino acid increased. Cheese lightness decreased as ripening time increased, while elasticity and hardness decreased. Principal Component Analysis was useful in discriminating cheeses according to their physicochemical composition and that allowed cheeses to be classified in two groups according to their ripening time and this resulted in those with less than 60 days and those with more than 90 days of ripening. Compared with cheeses ripened at 1 and 90 days, aged cheeses at 180 days reduced scores for appearance, color, odor, taste, texture and overall acceptance. Overall, Manchego-style cheeses from hair sheep had the usual ripened-cheese physicochemical changes.

Changes in Fatty Acid and Volatile Compound Profiles during Storage of Smoked Cheese Made from the Milk of Native Polish Cow Breeds Raised in the Low Beskids

This study investigated changes in the proximate chemical composition and profiles of fatty acids and volatile compounds of 12 smoked cheeses made from the milk of native Polish cow breeds used in Beskid Niski. Analyses were performed during the shelf life i.e., in the 1st, 21st, 42nd and 69th day of storage. Studies have shown that thanks to smoking and vacuum-packing, the chemical composition of cheese remained stable throughout the whole shelf-life. Up until the 21st day of storage, there were no statistically significant changes in the profile of fatty acids as well as volatile compounds. Changes were observed only after the mentioned storage time. After 21 days, there was a significant (p < 0.05) and steady decrease (up to day 69) in the proportion of odd-chain (by about 36%), branched-chain (by about 17%) and unsaturated fatty acids (by slightly over 1%). Among unsaturated fatty acids (p < 0.05), however, there was a significant increase in the proportion of monounsaturated fatty acids (by 5%) and a decrease in polyunsaturated fatty acids of nearly 12%. Storage lowered (by 47% in the 69th day of storage) the content of the conjugated linoleic acids (CLA), as well as lowered the n6 to n3 fatty acids ratio. During the 69 days of storage, the content of carboxylic acids increased to more than 50%. In the period from the 42nd to 69th day of cheese storage, the content of butyric acid and hexanoic acids increased twofold, whereas that of octanoic acid increased more than tenfold. Fifty-four volatile compounds were identified in the cheese. The largest group was ketones (34%), whose level decreased during storage, with 2-butanone, 3-hydroxy- (acetoin) and 2-butanone predominating. The research found that due to their low odor threshold, carboxylic acids may have negatively affected the flavor profile of the cheese.

Characterization of the key aroma compounds in Yunnan goat milk cake using a sensory-directed flavor analysis

To identify the key aroma compounds in Yunnan goat milk cake, seven varieties of milk cake samples were subjected to sensory analysis and gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), aroma recombination, omission, and addition tests. The GC-MS results revealed 53 compounds with aroma characteristics in all the samples. A further comparison of odor activity values and aroma intensities (AI) revealed 25 of these compounds as the initial key aroma compounds. The contributions of these key aroma compounds to the sensory attributes were determined using a partial least squares regression. Of these compounds, 2-heptanone and 2-nonanone were closely related to the "milky" and "cheesy" attributes and were highly abundant in the samples from Kunming. Fatty acids, including butanoic acid, hexanoic acid, octanoic acid, and decanoic acid, were the most abundant compounds detected in the milk cakes. These fatty acids were closely related to the "rancid" and "animalic (goat)" attributes and were largely detected in the samples from Dali Dengchuan and Dali Xiaguan. Sensory-directed aroma recombination, omission, and addition tests further validated the important contributions of ethyl butyrate, benzaldehyde, 3-methyl-1-butanol, 2-heptanone, hexanoic acid, and octanoic acid to the overall sensory properties. Moreover, ethyl butyrate, benzaldehyde, and 2-heptanone, when added, had evident inhibitory or masking effects on the AI of "sour," "rancid," and "animalic (goat)" attributes. PRACTICAL APPLICATION: Goat milk cake is a popular acid-curd cheese in Yunnan, China, however, our limited knowledge to its key aroma compounds restricts its development and industrial production. In this study, a sensory-directed flavor analysis was used to characterized the key aroma compounds of Yunnan goat milk cake, which will help to enhance our understanding on the flavor profile of Yunnan goat milk cake and provide a reference for optimizing the flavor feature and organoleptic quality of this fresh goat cheese.

Artisan minas cheese of Serro: proteolysis during ripening

The Artisan Minas Cheese (AMC) is the oldest and most traditional Brazilian cheese, it is produced in several regions of the state of Minas Gerais, such as the Serro region. The most striking features of the AMC-Serro are the use of raw milk and natural bacteria from the whey, popularly known as pingo, as well as the use of the rind washing process. The aim of the present study was to evaluate the proteolysis of the AMC-Serro from three different producers, during 60 days of maturation, and to relate the proteolysis to the producing farms, the production season and the rind washing during ripening. For this purpose, TRICINE-SDS-PAGE, proteolysis extension and depth indices, moisture, and texture (firmness) were evaluated. It was concluded that the temperature and moisture of the cheeses, that were determined by the location of the ripening room, the production season and the rind washing, were the most important factors. The degree of proteolysis also had an impact on the water loss during ripening, with effect on cheese safety. The results obtained in this study may be used to better understand the transformations during ripening of AMC-Serro and help the small traditional farmers to improve their product's quality and stability.

RESEARCH OF ORGANOLEPTIC PARAMETERS OF DUTCH CHEESE, PRODUCED FROM MILK OF COWS OF DIFFERENT BREEDS

The aim of this research is to study an influence of types of different breeds of milk cows on organoleptic properties of Dutch cheese at different rations of their food. It allows to receive cheese with prognosticated quality characteristics and to manage marketing strategies at cheese realization. The work presents the results of studying organoleptic properties of Dutch cheese, produced of milk of cows of different breeds, traditionally bred in the Northern-Eastern region of Ukraine. For studying an influence of cows feeding on exclusive properties of hard cheese, traditional food rations of cows were added with forages of a silage-hay type with Lucerne as a main source of proteins (44 % of the daily norm). Rations were practically identical with traditional ones by the content of energy and main food value factors and in general corresponded to norms of cows feeding. It has been demonstrated, that the high mark of cheese, up to 45 points for the taste and smell and total point mark 99 of 100 possible was obtained as a result of changing food rations at the expanse of introducing Lucerne silage in them. The data on optimization of food rations of certain cow breeds allow managing quality characteristics of milk and products of and are expedient for making cheese with unique regional characteristics. At conducting the comparative organoleptic assessment, there has been revealed a distinct dependence between a point mark of quality parameters of cheese on a breed of milk cows, and also on food rations of them. At the silage-hay food ration of animals, the received Dutch cheese had higher quality characteristics after 60 days of storage than cheese samples, obtained of cow milk at the traditional food ration.

Employment of L. paracasei K5 as a Novel Potentially Probiotic Freeze-Dried Starter for Feta-Type Cheese Production

In the present study, a novel potentially probiotic Lactobacillus paracasei strain, previously isolated from dairy products, was evaluated as a starter culture of Feta-type cheese production. Targeting industrial applications, the starter culture was applied as a ready-to-use freeze-dried culture that was either free or immobilized. The immobilized biocatalyst composed of Lactobacillus paracasei K5 cells absorbed within delignified wheat bran prebiotic carrier. All produced cheeses were compared with cheese manufactured by renin enzyme. Several parameters that affect acceptability, quality and shelf-life of Feta-type cheese were investigated, including microbial populations, physicochemical characteristics and cheese volatiles through 90 days of ripening and storage. Survival of L. paracasei K5 remained in high levels (≥6.0 log cfu/g) after the 90th day of cheese production, as recorded by combining microbiological enumeration and strain-specific multiplex PCR analysis. The use of the freeze-dried novel starter culture (free or immobilized) enhanced the aromatic profile of Feta-type cheeses. Finally, the use of the potentially synbiotic immobilized biocatalyst further improved aromatic characteristics of produced cheese and decrease of possible spoilage or pathogenic microorganisms. These findings indicate the potential industrial use of freeze-dried L. paracasei K5 as starter culture for the production of good-quality functional Feta-type cheese.