Effect Of Pasteurization Research Articles

Effect of sterilization methods on quality and storage characteristics of tofu fermented by lactic acid bacteria

This study examined the effects of pasteurization (PAS), ultrasonic sterilization (ULS), and microwave sterilization (MWS) on the quality and storage characteristics of brine-fermented tofu (BFT) and fermented tofu (FT). Comparative analysis revealed that MWS had a negligible detrimental effect on the structural integrity and organoleptic properties of BFT and FT, while effectively maintaining its water-holding capacity (WHC) and exhibiting the least impact on its texture. In contrast, PAS and ULS increased hardness and chewiness significantly (P < 0.05), but ULS also enhanced the brightness of tofu. Throughout the storage period, the WHC, elasticity, and sensory properties of tofu generally decreased, whereas the hardness and chewiness increased. PAS-BFT and MWS-FT maintained sensory quality for the longest periods of 14 and 12 days respectively, and could be decomposed to more small molecule peptides within 0–8 days and 0–6 days, which are more easily to be absorbed by the body. The findings discovered that MWS is the most suitable method for sterilization of tofu, with superior capability in maintaining the quality, extending shelf life, and improving digestibility of tofu.

Ohmic pasteurization of probiotic chocolate dairy desserts and its quality attributes

The study evaluated the effects of conventional pasteurization and ohmic heating (OH) at different electric fields (12, 16, 20, or 24 V/cm−1) on probiotic chocolate dairy desserts’ physicochemical, microbiological, sensory properties and volatile profiles. Both treatments were analyzed for parameters such as pH, syneresis, cream stability index, rheology, bioactive compounds (total phenolics and antioxidant capacity), and probiotic viability (Lactobacillus acidophilus LA-05) over a 28-day storage period. Ohmic heating at higher electric fields (20 and 24 V/cm−1) showed comparable results to pasteurization for most parameters, with non-significant differences or even higher values for some. Sensory analysis revealed that pasteurized samples were more associated with “creamy” and “firm” textures. In contrast, OH-treated samples were linked to lumps and fluidity, particularly in OH24 and OH16, respectively. Volatile compounds such as propanal and ethyl propanoate were detected across treatments, with ethyl acetate unique to OH24. The results suggest that OH, especially at higher electric fields, is a promising technology for processing probiotic dairy desserts, offering similar or enhanced qualities compared to conventional pasteurization. These findings provide insights into the potential for OH to be routinely applied in functional dairy product production.

Effect of pasteurization on the physicochemical and nutritional quality of milk from the Korhogo dairy

Stabilization of the nutritional value of milk is essential for its conservation. It is in this context that the aim of this study was to evaluate the nutritional quality of raw and pasteurized cow's milk produced in Korhogo with a view to its valorization. Raw and pasteurized milk were sampled from June 24 to July 13, 2024, at the Korhogo dairy. The physicochemical and nutritional parameters of the two types of milk were determined according to AOAC methods. The results of the physicochemical parameters revealed that the values ​​of pH, acidity, dry matter and degree brix are respectively 6.64 ± 0 .01 and 6.90 ± 0.00; 18.00 ± 0.10; 16.20 ± 0.04 °D; 121.93 ± 0.64; 126.23 ± 2.19 g/L and 10.10 ± 0.10; 11.20 ± 0.10 °Brix for raw and pasteurized milk. The nutritional parameters of raw and pasteurized milk show significant contents of ash (7.00 ± 0.01 and 7.47 ± 0.01 g/L), lipids (40.80 ± 0.02 and 36.30 ± 0.46 g/L), proteins (40.71 ± 0.01 and 37.02 ± 0.01 g/L) and carbohydrates (33.42 ± 0.03 and 45.44 ± 0.04 g/L). Pasteurization could be used to stabilize the nutritional value of milk.

Phenolic compounds' stability in reduced-calorie plum spread fortified with freeze-dried plum pomace: Effects of processing techniques and pasteurization

Fortified reduced-calorie plum spreads (∼40°Brix), containing 10 % (w/w) freeze-dried plum pomace (FD-PP), were analyzed for phenolic compounds (spectrophotometrically and chromatographically determined) and antioxidant activity to evaluate the effects of processing and pasteurization during the transition from laboratory (LS-S) to industrial scale (IS-S) spread manufacturing. Additionaly, a control sample at an industrial scale (IS-CS) was prepared to estimate FD-PP's functional contribution. The physicochemical properties of spreads and plum materials used (FD-PP and plum purée, PP), were also investigated. IS-S exhibited increased levels of total phenols, total flavonoids, total anthocyanins, catechin, chlorogenic acid, caffeic acid, rutin, quercetin, cyanidin 3-O-glucoside, and cyanidin 3-O-rutinoside, alongside higher antioxidant activity compared to IS-CS. LS-S retained more phenolics than IS-S, possibly due to the pasteurization step (85 °C, 1 h) introduced in IS-S processing. Although characterised by reduced phenolic and anthocyanins content upon pasteurization, appealing colour of the IS-S spread was retained. Significant correlations (p<0.05) were observed across most individual phenolic compounds and antioxidant activity. Standard score (SS) analysis showed that phenolic retention and antioxidant activity were highest in LS-S (SS=0.754), followed by IS-S (SS=0.490) and IS-CS (SS=0.163). Pasteurization and the use of FD-PP contributed to the microbiologically stable spread after 21 days of storage.

Effect of gamma irradiation and thermal pasteurisation on functional quality of liquid whole egg

The present study aimed to assess the effect of gamma irradiation and thermal pasteurisation on the functional quality of liquid whole egg. Three separate liquid whole egg (LWE) homogenate samples were used in the study: Control untreated LWE (C), gamma irradiated at a previously validated pasteurisation dose of 3kGy, and thermally pasteurised at a core temperature of 60±1°C for 3.5 min (T). Samples were analysed for their functional properties on the day of pasteurisation.The foaming capacity and foaming stability were significantly (p&lt;0.05) higher, whereas the viscosity was significantly (p&lt;0.05) lower for G when compared to C and T. The emulsifying capacity of G was significantly (p&lt;0.05) lower than C, whereas emulsifying stability of G did not differ significantly from C. According to the findings of this study, subjecting the LWE to gamma irradiation at 3kGy, showed no alterations in emulsifying capacity whereas foaming capacity and foaming stability was improved, when compared to the untreated control (C). The G showed lower viscosity and emulsifying stability Keywords: Liquid whole egg, cold pasteurised, thermally pasteurised, functional properties

Effectiveness of pasteurization for the inactivation of H5N1 influenza virus in raw whole milk

Highly pathogenic avian influenza (HPAI) clade 2.3.4.4b H5Nx viruses continue to cause episodic incursions and have been detected in more than 12 taxonomic orders encompassing more than 80 avian species, terrestrial and marine mammals, including lactating dairy cows. HPAI H5N1 spillover to dairy cattle creates a new interface for human exposure and raises food safety concerns. The presence of H5N1 genetic material in one out of five retail pasteurized milk samples in the USA has prompted the evaluation of the pasteurization processes for the inactivation of influenza viruses. Our study examined whether pasteurization could effectively inactivate HPAI H5N1 spiked into raw whole milk. First, we heated 1 mL of non-homogenized cow milk samples to attain an internal temperature of 63°C or 72°C and spiked with 6.3 log10 EID50 of clade 2.3.4.4b H5N1 virus. Complete inactivation was achieved after incubation of the H5N1 spiked raw milk at 63°C for 30 min. In addition, viral inactivation was observed in seven of eight experimental replicates when treated at 72°C for 15s. In one of the replicates, a 4.44 log10 virus reduction was achieved, which is about 1 log higher than the average viral quantities detected in bulk milk in affected areas. Therefore, we conclude that pasteurization of milk is an effective strategy for mitigation of the risk of human exposure to milk contaminated with H5N1 virus.

The contribution of sturgeon species and processing conditions on caviar texture, metabolomic profile and sensory traits

A comprehensive evaluation of the attributes that determine caviar quality, including sturgeon species and processing methods, is still lacking in the scientific literature. In this study, eight types of caviar, obtained from six different sturgeon species and produced using either salt or a combination of salt and sodium tetraborate (E285) with pasteurization, were characterized through untargeted metabolomics, sensory analysis, and texture evaluation. The results showed that Huso huso caviar was rich in gamma-glutamyl peptides (contributing to a kokumi taste), while the other sturgeon species were primarily distinguished by lipids (mainly glycerophospholipids) and nucleotides (such as AMP, inosinic acid, and other metabolites driving umami taste). Moreover, untargeted metabolomics revealed the technological effects of salting and pasteurization. Sensory analysis identified crunchiness, color homogeneity, and darkness as the main traits differentiating the products. Butter, hazelnut, and briny flavours were also key characteristics of the caviar.

Effects of high temperature short time (HTST) pasteurization on milk and whey during commercial whey protein concentrate production

Two pasteurization steps are often used in the preparation of whey protein concentrate (WPC) before evaporation into a dry product. The Pasteurized Milk Ordinance (PMO) in the United States requires that raw bovine milk be pasteurized using a process that meets minimum heat treatment requirements to achieve reductions in pertinent microorganisms. In addition, WPC produced from USDA-approved plants must comply with CFR Subpart B §58.809, which dictates that all fluid whey used in the manufacture of dry whey products shall be pasteurized before being condensed. These heat treatments are effective at inactivating the most thermally resistant bacterium, such as Coxiella burnetii; however, they can also alter milk proteins-inducing denaturation, aggregation and reduced bioactivity. Though the impact of thermal treatments on whey proteins has been examined, the specific influence of 2 high-temperature-short-time (HTST) pasteurization steps on the retention of proteins in WPC remains unknown. This study aimed to investigate the effect of commercial-scale HTST pasteurization of both raw milk and the resulting sweet whey on the products' overall protein profile. Three distinct batches of raw milk (RM) and corresponding pasteurized milk (PM), the resulting whey (RW) and pasteurized whey (PW) produced at commercial scale were analyzed. Assessments of denaturation were conducted through solubility testing at pH 4.6 and hydrophobicity evaluation via anilinonaphthalene-1-sulfonic acid assay (ANS). Additionally, enzyme-linked immunosorbent assay (ELISA), PAGE (PAGE) and liquid chromatography tandem mass spectroscopy (LC-MS/MS) were employed to compare the retention of key bioactive proteins before and after each HTST pasteurization step. The percentage of soluble whey protein decreased from RM to PM and from RW to PW, but no significant differences were observed via hydrophobicity assay. ELISA revealed a significant reduction in key bioactive proteins, such as lactoferrin, immunoglobulin A and immunoglobulin M, but not immunoglobulin G, after HTST pasteurization of RM and RW. PAGE and LC-MS/MS revealed a significant decrease in the retention of lactoferrin and key milk fat globular membrane proteins, such as xanthine dehydrogenase oxidase/xanthine oxidase, lactadherin and fatty acid binding protein. Additionally, xanthine oxidase activity was significantly reduced after HTST pasteurization of milk and whey. This research helps to identify the limitations of the current processing techniques used in the dairy industry and could lead to innovation in improving the retention of bioactive proteins.

Enhancing Biogas Production: An Assessment of Pasteurization Effects on Poultry, Swine, Bovine Manure and Food Waste Substrates

Within the evolving regulatory landscape of the European Union concerning animal by-product (ABP) management within the circular economy framework, this study explores the concurrent objectives of safeguarding public health and environmental integrity and maximizing final product value. Anaerobic digestion (AD) emerges as a holistic solution for ABP management, addressing sanitation concerns while enhancing end-product quality. Through laboratory-scale experimentation, the AD process applied to four substrates—poultry manure, swine manure, cattle manure, and food waste—is scrutinized. Prior to AD, pasteurization at 70 °C for 60 min ensures microbial safety. Subsequently, four experimental AD cycles compare pasteurized and unpasteurized substrates. Results highlight the efficacy of pasteurization in sanitizing final products across all substrates, emphasizing its pivotal role in product safety. However, pasteurization’s impact on system performance varies. While enhancing biogas yield from animal waste notably, its influence on food waste biogas production is less pronounced, indicating substrate-specific dynamics. This study offers insights into optimizing ABP management strategies, emphasizing the interplay between pasteurization, substrate characteristics, and AD performance. Such insights are crucial for advancing sustainable practices in the circular economy paradigm, balancing environmental stewardship with economic viability.

Effect of pasteurization and storage on the bioavailability of milk proteins during in vitro intestinal digestion and Caco-2 cell transport

This study fills a specific knowledge gap by comprehensively investigating the intestinal digestive dynamics and transport kinetics of pasteurized milk proteins during cold storage, utilizing dynamic in vitro digestion models, human colorectal adenocarcinoma cell line (Caco-2) transport simulations, peptideomics and amino acid analysis. The content of free amino acids during intestinal digestion and their transport capacity (excluding lysine) were highest in pasteurized milk stored for 7 days (PAST-D7), intermediate in pasteurized milk stored for 0 days (PAST-D0) and lowest in raw milk (RM). Conversely, the quantity and intensity of bioactive peptides during digestion decreased with pasteurization and storage. Additionally, pasteurization and storage reduced the intensity of bioactive peptides transported through Caco-2 cells and the types and intensity of potential allergenic peptides. These findings indicate that while pasteurization and storage may diminish some physiological benefits of milk, they may also enhance protein bioavailability and reduce allergenicity.

Effect of Heat Pasteurization and Enzymatic Maceration on Yield, Color, Sugars, Organic Acids, and Phenolic Content in the ‘Merlot Kanthus’ Grape Juice

Effect of Heat Pasteurization and Enzymatic Maceration on Yield, Color, Sugars, Organic Acids, and Phenolic Content in the ‘Merlot Kanthus’ Grape Juice

Effects of Pasteurisation on Antioxidant Activities and Microbiological Properties of Stingless Bee Honey Beverage During Storage

Effects of Pasteurisation on Antioxidant Activities and Microbiological Properties of Stingless Bee Honey Beverage During Storage

Impact of Pasteurisation on Terpenes, Terpenoids, Aldehydes and Esters in Hoppy Ales on Ageing

Pasteurisation is a common technique to achieve microbial stability of beer. In dry hopped beer, pasteurisation is the ultimate measure to assure product quality and consumer safety. To gain insights into the effects of pasteurisation on the chemistry of hoppy ales the time related changes of aldehydes, terpenes, terpenoids and esters in an unpasteurised and pasteurised session India Pale Ale (SIPA), two IPAs, and a double IPA (DIPA) were monitored. The ales were stored at 4 °C and 20 °C for 52 wk to evaluate chemical differences between the two treatments. It was found that pasteurisation led to an immediate increase of staling aldehydes (i.e., furfural and 2-methylpropanal), a decrease of fermentation esters (e.g. ethyl octanoate) and hop related esters (e.g. 2-methylbutyl isobutyrate) in fresh beer, while terpenes and terpenoids were hardly affected. When the beers were stored, unpasteurised ales were chemically less stable compared to the pasteurised ones. Differences between pasteurised and unpasteurised ales were dependent on storage temperature. The results of this study highlight that pasteurisation is favourable when aiming to achieve an increased shelf life of up to 12 months, as the negative influence of the heat impact is compensated after 1 month of storage at ambient (20 °C) temperature.

Combined Metabolomic and NIRS Analyses Reveal Biochemical and Metabolite Changes in Goat Milk Kefir under Different Heat Treatments and Fermentation Times.

Dairy products are an important source of protein and other nutrients in the Mediterranean diet. In these countries, the most common sources of milk for producing dairy products are cow, goat, sheep, and buffalo. Andalusia is traditionally the largest producer of goat milk in Spain. Kefir is a fermented product made from bacteria and yeasts and has health benefits beyond its nutritional properties. There is a lack of knowledge about the molecular mechanisms and metabolites that bring about these benefits. In this work, the combination of analytical techniques (GC-FID, UHPLC-MS-QToF, GC-QqQ-MS, and GC-ToF-MS) resulted in the detection of 105 metabolites in kefir produced with goat milk from two different thermal treatments (raw and pasteurized) fermented at four time points (12, 24, 36, and 48 h, using 0 h as the control). Of these, 27 metabolites differed between kefir produced with raw and pasteurized milk. These changes could possibly be caused by the effect of pasteurization on the microbial population in the starting milk. Some interesting molecules were identified, such as shikimic acid, dehydroabietic acid, GABA, and tyramine, which could be related to antibacterial properties, strengthening of the immune system, and arterial pressure. Moreover, a viability assay of the NIRS technique was performed to evaluate its use in monitoring the fermentation and classification of samples, which resulted in a 90% accuracy in comparison to correctly classified samples according to their fermentation time. This study represents the most comprehensive metabolomic analysis of goat milk kefir so far, revealing the intricate changes in metabolites during fermentation and the impact of milk treatment.

Characterizing and decoding the key odor-active compounds in fresh, pasteurized, and high pressure processing sea buckthorn (Hippophae rhamnoides L.) juice

The non-thermal and thermal effects on aroma of sea buckthorn juice have rarely been investigated. In this study, 57 odor compounds were identified in fresh sea buckthorn juice (FSBJ), high pressure processing sea buckthorn juice (HSBJ), and pasteurized sea buckthorn juice (PSBJ), including 29 esters, 8 aldehydes, 1 ketone, 5 alcohols, 5 acids, 6 terpenoids, and 3 others. Ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl hexanoate, and ethyl 2-hydroxy-3-methylbutanoate with flavor dilution factors ranging from 729 to 59,049 contributed to the fruity odors of FSBJ and HSBJ. Besides, the formation of off-odor compounds including hexanal, nonanal, furfural, 3-methylbutanoic acid, and dimethyl disulfide with odor activity values ≥ 1, imparts fatty, roasted, sweaty, and cooked odor in PSBJ. The variations of vitamin C and reducing sugar are significantly associated with changes in odor-active compounds during pasteurized processing. These findings provide new insights that high pressure processing minimizes the adverse effects of pasteurization.

Does pasteurization inactivate bird flu virus in milk?

ABSTRACT Recently, an outbreak of highly pathogenic avian influenza A (H5N1), which carries the clade 2.3.4.4b hemagglutinin (HA) gene and has been prevalent among North American bird populations since the winter of 2021, was reported in dairy cows in the United States. As of 24 May 2024, the virus has affected 63 dairy herds across nine states and has resulted in two human infections. The virus causes unusual symptoms in dairy cows, including an unexpected drop in milk production, and thick colostrum-like milk. Notably, The US Food and Drug Administration reported that around 20% of tested retail milk samples contained H5N1 viruses, with a higher percentage of positive results from regions with infected cattle herds. Data are scant regarding how effectively pasteurization inactivates the H5N1 virus in milk. Therefore, in this study, we evaluated the thermal stability of the H5 clade 2.3.4.4b viruses, along with one human H3N2 virus and other influenza subtype viruses, including H1, H3, H7, H9, and H10 subtype viruses. We also assessed the effectiveness of pasteurization in inactivating these viruses. We found that the avian H3 virus exhibits the highest thermal stability, whereas the H5N1 viruses that belong to clade 2.3.4.4b display moderate thermal stability. Importantly, our data provide direct evidence that the standard pasteurization methods used by dairy companies are effective in inactivating all tested subtypes of influenza viruses in raw milk. Our findings indicate that thermally pasteurized milk products do not pose a safety risk to consumers.

Effect of pasteurization, dehumidification, refrigeration and maturation on the composition, quality and acceptability of Scaptotrigona depilis honey

Honey from stingless bees has parameters that are different from those produced by Apis mellifera. These differences have led to studies of honey conservation techniques. In this context, it is necessary to evaluate whether the use of different conservation processes impacts the quality and chemical composition of this type of honey. The aim of this study was to conduct sensory analysis and determine the chemical profile, quality, and antioxidant activity of S. depilis honey subjected to different conservation processes. The physicochemical characteristics were determined in the fresh sample (time-point zero sample) and after freezing, pasteurization, dehumidification and maturation for 180 days. The reducing sugar, apparent sucrose, total acidity, moisture, water-insoluble solids, minerals, diastatic activity, Brix, color and hydroxymethylfurfural (HMF) levels were determined. These samples were also evaluated for their volatile composition and sensory aspects. After 180 days, the processed honeys showed changes in the phenolic content, and dehumidification was the treatment that most interfered with the phenolic content of the samples. The physicochemical properties that presented significant differences were the acidity, moisture, diastatic activity and color for the matured honey and the HMF levels in the dehumidification and pasteurization treatments. The main volatile compounds differed in each treatment in relation to the untreated honey. The sensory acceptance test showed significant differences for some of the attributes evaluated and the preference of consumers was for the untreated honey.

Effect of Lactiplantibacillus plantarum CNPC003 and milk pasteurization on artisanal goat coalho cheese characteristics

This study evaluated the effect of adding Lactiplantibacillus plantarum CNPC003 (LP) and applying milk pasteurization on the microbiological, technological, and physicochemical characteristics and protein profile of artisanal goat coalho cheese during 60 days of ripening. Four types of cheese were produced, including cheeses made with raw and pasteurized goat milk and with and without LP (RC, PC, RCLP, and PCLP). All cheeses were safe for consumption and maintained high lactic acid bacteria counts (above 8 log CFU mL−1) at the end of the ripening period. RC and RCLP showed higher hardness and lower chewiness than cheeses made with pasteurized milk (PC and PCLP) after 60 days of ripening. As expected, there was a reduction in lactose content with a simultaneous increase in acidity and syneresis for all cheeses over the 60 days of ripening, with no significant change in the other evaluated physicochemical parameters. Proteolysis rates increased in all cheeses up to 60 days of ripening, aligning with elevated levels of soluble protein and free amino acids. After 60 days of ripening, PC showed a higher extent of proteolysis index, higher amount of high molecular weight peptides, higher number of identified proteins, and lower content of free amino acids. RCLP showed a higher depth of proteolysis index, higher free amino acids amount (1583 ± 3.95 mg 100 g−1), and fewer identified proteins. Among the peptides identified, it was possible to define 30 potential bioactive peptides according to the bioactivity score (>0.5), where both cheeses added with LP had 18 of these peptides, mostly potentially ACE inhibition sequences. The addition of LP and the pasteurization of milk positively affected the microbiological safety of ripened coalho goat cheeses, primarily contributing to the differentiation of their texture and protein and bioactivity profile.

The effect of pasteurisation and storage on aroma compounds in lager

Why was the work done: To investigate the impact of pasteurisation and storage in bottle on aroma compounds in pale lager beer. How was the work done: Pale lager beer was produced at an industrial scale with 100% pilsner malt and a bottom fermenting yeast. Samples were taken of unpasteurised beer from bright beer tank, after flash pasteurisation and six months after packaging in amber glass bottles. What are the main findings: Post pasteurisation, a marked increase was found in the concentration of 2,3-pentanedione (50%) and diacetyl (33%), presumably reflecting the decomposition by heat of precurser acetohydroxy acids. There was also a marginal increase in dimethyl sulphide (6%) with little or no change in other aroma compounds. Storage for six months in bottle, also resulted in an increase in the level of 2,3-pentanedione, diacetyl and dimethyl sulphide. The linear (Pearson) correlation was &gt; 0.8 for both dimethyl sulphide and diacetyl, and 2,3-pentanedione and diacetyl. Accordingly, it was concluded that the levels in beer of dimethyl sulphide and 2,3-pentanedione are proportionally related to diacetyl. Why is the work important: This work provides an insight into the effects on flavour and aroma of lager of flash pasteurisation and subsequent storage in bottle. The inter-relationship between aroma compounds in beer suggests that such synergies may undermine the sensory perception of threshold levels and identification of specific aromas.

Effects of Vacuum Pasteurization on the Nutritional, Sensory and Microbiological Properties of Orange (Citrus × sinensis) and Carrot (Daucus carota L.) Nectar

This study involved the evaluation of the effect of vacuum pasteurization on physicochemical characteristics (pH, total soluble solids, titratable acidity, chroma, tone, IO, vitamin C, 5-hydroxymethylfurfural), microbiological properties (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, total coliforms, total mesophilic aerobes, molds and yeasts) and sensory characteristics of orange and carrot nectar. The thermal treatments were designed based on the thermal lethality of two heat-resistant microorganisms typical of the product (Neosartorya fischeri and Zygosaccaromyces bailii). The evaluation was carried out on raw nectar and pasteurized nectar. The shelf life was estimated to be 30 days (6 °C). The most favorable results were obtained by applying a heat treatment at 88 °C for 32.68 min, managing to retain 85.87% of vitamin C and a microbiological stability of 12 days (6 ± 0.6 °C) with regard to total mesophilic aerobes. Likewise, the tasters established that this treatment resulted in the best flavor, texture and acceptability characteristics.