UHT Milk Research Articles

The administration of UltraMimi Kids® UHT milk by PT. Ultrajaya Milk Industry increased body weight and did not increase estrogen hormone level in female albino rat (Rattus norvegicus) Wistar strain

Background: This study aimed to prove that administration of UltraMimi Kids® UHT milk by PT. Ultrajaya Milk Industry increased body weight and estrogen levels in female albino rat (Rattus norvegicus) Wistar strain.
 Methods: This research was a true experimental with randomized pretest-posttest control group design. The research subjects were 18-female-albino-rats aged 21-days, weight 25-28 grams, divided into 2-groups: control group which was given standard food and sugar solution (0.36 grams of sugar dissolved in 1 ml aquadest), and intervention group which was given standard food and UltraMimi Kids® UHT milk 1 ml for the first 14-days and upgraded to 2 ml for the rest 14-days, given three times a day for 28-days. The rats body weight and estrogen levels were measured using Tanita-KD-192-digital-scales and ELISA method.
 Results: The control group had an increased body weight (26.2±1.2-66.1±5.94 grams; p<0,001), but there was no change in estrogen levels (38.59±11.19-44.59±5.42 ng/L; p=0.217). Whereas, the intervention group had an increased body weight (25.77±0.83-85.33±10.24 grams; p=0.008), but there was no change in estrogen levels (39.91±3.73-42.66±2.24 ng/L; p=0.066). After 28-days of intervention (posttest), it was found that the mean of body weight in the intervention group was higher than the control group (p<0.001), there was no significant difference in estrogen levels (p=0.339) and food intake from the remaining feed in both groups (0.51±0.81-0.36±0.55 grams; p=0.823).
 Conclusion: The administration of UltraMimi Kids® UHT milk by PT. Ultrajaya Milk Industry increased body weight and did not increase estrogen hormone level in female albino rat (Rattus norvegicus) Wistar strain.

Protective effect of inulin on thermally treated acerola juice: in vitro bioaccessibility of bioactive compounds

Prebiotic (PREB) and non-PREB acerola juice were subjected to HTST (high-temperature short time) and UHT (ultra-high temperature) processing. A simulated in vitro digestion allowed the bioaccessibility evaluation of the bioactive compounds and the juice composition. NMR and chemometrics were applied to evaluate the changes of processed and non-processed juices. Inulin (IN) had a protective effect in preserving the organic compounds after thermal processing and with the three main stages of in vitro simulated digestion. Both thermal processes increased ethanol, malic acid, choline; fructose; α and β-glucose, and 2-furoic acid (a degradation product of vitamin C) after simulated digestion. For the PREB juices, the addition of IN protected against the pH and the digestive enzymes in acerola juice samples. In thermally processed juices, IN increased vitamin C and total phenolic bioaccessibility. The bioaccessibility of 2-furoic acid increased with the progression of the digestive phases. The presence of IN did not prevent 2-furoic acid formation. However, the amount of these compounds was significantly lower in PREB samples. Thus, thermal processing is a suitable technology for acerola juice preservation, maintaining the vitamin C level despite some formation of 2-furoic acid. Besides a PREB effect, IN also improved the bioactive compounds' bioaccessibility in the treated juice.

Antimicrobial Activity and Chemical Characterization of a Non-Polar Extract of Saffron Stamens in Food Matrix.

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.

Assessment of the production of Bacillus cereus protease and its effect on the quality of ultra-high temperature-sterilized whole milk

Bacillus cereus is one of the most important spoilage microorganisms in milk. The heat-resistant protease produced is the main factor that causes rotten, bitter off-flavors and age gelation during the shelf-life of milk. In this study, 55 strains of B. cereus were evaluated, of which 25 strains with protease production ability were used to investigate proteolytic activity and protease heat resistance. The results showed that B. cereus C58 had strong protease activity, and its protease also had the highest thermal stability after heat treatment of 70°C (30 min) and 100°C (10 min). The protease was identified as protease HhoA, with a molecular mass of 43.907 kDa. The protease activity of B. cereus C58 in UHT-sterilized whole milk (UHT milk) showed an increase with the growth of bacteria, especially during the logarithmic growth phase. In addition, the UHT milk incubated with protease from B. cereus C58 at 28°C (24 h) and 10°C (6 d) were used to evaluate the effects of protease on the quality of UHT milk, including protein hydrolysis and physical stability. The results showed that the hydrolysis of casein was κ-CN, β-CN, and αS-CN successively, whereas whey protein was not hydrolyzed. The degree of protein hydrolysis, viscosity, and particle size of the UHT milk increased. The changes in protein and fat contents indicated that fat globules floated at 28°C and settled at 10°C, respectively. Meanwhile, confocal laser scanning microscopy images revealed that the protease caused the stability of UHT milk to decrease, thus forming age gelation.

Physico-chemical changes during processing and storage of UHT milk

In this study, physico-chemical and heat induced changes during the preparation and storage of UHT milk were evaluated. Parameters such as pH, acidity, viscosity, sedimentation, colloidal calcium (Ca), colloidal magnesium (Mg), hydroxyl methyl furfural (HMF), lactulose and color value were evaluated. During conversion of raw milk to UHT milk, there was slight increase in viscosity, colloidal Ca, colloidal Mg, HMF, lactulose and colour value, while decrease in pH value was observed. During storage of UHT processed milk there was significant (p<0.001) increase in viscosity, a value, b value, HMF and lactulose content, whereas a significant (p<0.001) decrease in pH, colloidal Ca, colloidal Mg and L value was observed. Increase in acidity, sedimentation content and formation of Maillard browning products adversely affected the quality of UHT milk. These changes were noticed more in UHT processed milk stored at 30°C vis-a-vis 5°C.

Physicochemical changes and age gelation in stored UHT milk: Seasonal variations

The physicochemical changes and the occurrence of age gelation during the storage of indirect UHT milk produced in different seasons in New Zealand were examined. UHT milk produced in the early season had the lowest protein and calcium contents, the smallest mean particle size when fresh, and the lowest propensity for age gelation. During storage, the changes in pH, ionic calcium concentration, particle size, and protein profiles of the milk and serum did not vary greatly between the seasons. Protein analysis indicated that the Maillard reaction and limited proteolysis occurred during the storage of UHT milk. The heat-induced aggregation among partially κ-casein-depleted casein micelles might play a part in the physicochemical gelation of UHT milk during storage.

Real-Time Detection of Fouling-Layer with a Non-Intrusive Continuous Sensor (NICS) during Thermal Processing in Food Manufacturing

The fouling of indirect shell and coil heat exchanger by heavy whipping cream (HWC) and non-fat dry milk (NFDM) was studied at aseptic Ultra-High Temperature (UHT) processing conditions (140 °C) using a novel non-intrusive sensor. The sensor emitted a heat pulse intermittently throughout the duration of the process causing an incremental increase in temperature at the tube external surface. The temperature response of the sensor varied due to the radial growth of the fouling layer formed by certain components of the products. Each heating pulse and the temperature response was studied to estimate the thermal conductivity of the fouling layer using inverse problems and parameter estimation. The changes in thermal conductivity were used as an indication of the fouling layer development during food processing at UHT temperatures. The estimated parameters from experimental results showed a decreasing trend in the thermal conductivity of HWC and NFDM from 0.35 to 0.10 and 0.63 to 0.37, respectively. An image analysis tool was developed and used to measure the fouling layer thickness at the end of each trial. The measured thickness was found to be 0.58 ± 0.15 for HWC and 0.56 ± 0.07 mm for NFDM. The fouling layer resistance for HWC and NFDM was 5.95 × 10−3 ± 1.53 × 10−3 and 1.53 × 10−3 ± 2.0 × 10−4 (m2K)/W, respectively.

Alkaline cleaning of ultra-high temperature dairy fouling in a laminar flow regime

The formation of deposits on surfaces is unavoidable in the food industry, but deposits increase the resistance to fluid flow and hamper the heat transfer necessary for, e.g., pasteurisation or sterilisation of dairy products. While deposits from pasteurisation processes are optimally cleanable at an established sodium hydroxide concentration, information on cleaning of dairy deposits from ultra-high temperature processes is limited. The cleaning of ultra-high temperature deposits from dairy products is discussed, using model foulants from whey protein concentrate and medium heated skimmed milk powder. Deposits were generated reproducibly in a shear-free batch apparatus on electrically heated stainless steel plates with constant surface temperatures of 85 °C and 125 °C. The subsequent cleaning of these test samples in an external laminar operated flow channel at an average bulk temperature of 75.5 °C show a shift of an optimal concentration of sodium hydroxide of ultra-high temperature fouling compared with low temperature fouling.

Smartphone-based digital images as a novel approach to determine formaldehyde as a milk adulterant

Milk is an important source of protein and its consumption has gained relevance because of new evidence for its nutritional and functional role for humans. On the other hand, milk quality has been hindered by tampering, including the addition of formaldehyde to mask product deterioration and increase its shelf life, although this substance may cause harm to consumers. Taking these aspects into account, a novel, fast, greener, portable, and cost-effective method is proposed for the determination of formaldehyde in milk. This method relies on smartphone-based digital image colorimetry of the product formed upon reaction with the Schiff reagent, followed by conversion of the images into RGB values using free application software. Sample preparation only involved protein precipitation in an acidic medium and analyte determination required only a few micrograms of the reagents. The proposed method achieved a limit of detection as low as 120 μg L−1 formaldehyde with a linear response up to 1250 μg L−1 and good precision (CV = 2%, n = 20). Matrix effects were negligible after protein precipitation with recoveries of formaldehyde spiked milk samples within 92–106%. The accuracy was assessed using a reference procedure (HPLC with UV detection after analyte derivatization and liquid–liquid extraction) and the results agreed at the 95% confidence level. The procedure is applicable to whole, semi-skim, and skim milk processed using pasteurization or ultra-heat treatment (UHT).

Aflatoxin M1 in pasteurized and UHT milk marked in Morocco

Milk plays an essential role in a balanced diet for human health. Mycotoxins are among the most toxic compounds found in milk of lactating cows. The purpose of this work was to assess aflatoxin M1 (AFM1) levels in 67 liquid milk samples (46 pasteurized and 21 UHT) randomly collected during 2019 from supermarkets and dairy shops in four Moroccan cities (Casablanca (n = 27), El Jadida (n = 10), Fez (n = 18) and Meknès (n = 12)). AFM1 was determined in milk by liquid chromatography (LC) after immunoaffinity column (IAC) cleanup. Analytical results indicated that out of the 67 analyzed samples, 9 (13.4%) were considered as positively contaminated, while 58 samples (86.6%) had AFM1 under the detection limit. For positive samples, AFM1 levels ranged between 10 and 77 ng/L, with an overall average value of 4.46 ± 14.09 ng/L. It has to be underlined that only one pasteurized milk sample contained AFM1 at concentration (77 ng/L) that exceeded the Moroccan maximum regulatory limit of 50 ng/L, while 100% of milk samples were below the limit of 500 ng/kg set by Codex Alimentarius standards. Based on the contamination levels found in this study and milk consumption data in the country, the estimated exposure level of Moroccan adults to AFM1 from milk was estimated at 0.88 ng/person/day (0.0125 ng/kg b.w./day). This exposure level is considered higher than the dietary intakes estimated by JECFA for the Middle Eastern and the African diets.

β-galactosidase from Kluyveromyces lactis in genipin-activated chitosan: An investigation on immobilization, stability, and application in diluted UHT milk

The objective of this research was to evaluate the immobilization of the enzyme β-galactosidase in a genipin-activated chitosan support. The influence of the number of spheres and substrate concentration on immobilization yield (IY) and enzyme activity (EA) was analyzed using experimental design. Thermal, operational and storage stabilities were assessed, and the enzymatic derivatives were characterized by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The TGA showed that the enzymatic derivatives kept their thermal behavior, and the SEM images revealed smooth surfaces in all the spheres. The optimized conditions for the immobilization process were 4.57 mg·mL−1 of spheres and a substrate concentration of 10 mM (IY = 84.13%; EA = 24.97 U·g−1). Thermal stability was enhanced at 10 and 37 °C, enabling four successive cycles of lactose hydrolysis in diluted UHT milk. Therefore, the immobilized enzyme in genipin-activated chitosan has potential for lactose hydrolysis and applications in the food industry.

Vitik Detection of Aerobic Spore-Forming Bacteria Isolated from Raw Milk, Skim Milk Powder and UHT Milk

Background Aerobic spore-forming bacteria can be found in a wide range of environmental niches suchas food production. Among them, the aerobic spore-forming bacteria like Bacillus ceruse, pose a risk ofcausing dairy product poisoning by the production of toxins.Materials and Method: Out of 40 samples, 10 from each of Raw Milk, Skim Milk Powder, UHT Milk andWight chees were collected to isolate aerobic spore-forming bacteria by morphological, physiological andbiochemical tests.Conclusion: A total of 25 isolates of heat resistant bacteria, 10(40%), 8(32%), 3(12%), 4(16%) from “RM,white chees, SMP and UHT milk respectively,” were purified and characterized. Various spore formingbacteria belonging to Bacilli spp. which include pathogenic were biochemically identified using vitek 2systems, the result showed the highest rate of Bacillus subtilis (28%) followed by Bacillus ceruse andBacillus thuringiensis (24%).

Validation of a Multiclass Method for the Screening of 15 Antibiotic Residues in Milk Using Biochip Multi-array Technology and Its application to Monitor Real Samples.

Veterinary drugs are extensively and legally consumed to treat and prevent disease in chattels but some are also used illegally as growth-stimulating agents. Inappropriate or intensive use of antibiotics can cause allergic reactions and, above all, antibiotic resistance. A multiclass approach for the screening of antimicrobial substances in milk was validated in consonance with Commission Decision 2002/657/EC and to the European guideline for the validation of screening methods for veterinary medicines. This biochip-based approach enables the simultaneous determination of a total of 13 sulphonamide, dapsone and trimethoprim. For monitoring of antibiotic residues, 53 UHT milk samples collected from Tehran, IR Iran were screened applying this technology. The result showed that for all antibiotic residues, the positivity threshold T was much more than the cut-off value Fm. A false positive rate of less than 5% was found for all antibiotics which are satisfactory. All detection capabilities (CCβ) were well below the Maximum Residue Level (MRL) set by the European Commission (100 µg/kg for the sum of all sulphonamides and 50 µg/kg for trimethoprim in milk). The screening results of 53 milk samples showed that 71.7% of samples were compliant and all positive samples were below the MRL set by European Commission. This study showed that the biochip-based technique is valid to identify and quantify antibiotic residues in milk at the studied validation levels. The method was rapid, easy, safe, and able to screen 13 sulphonamide, dapsone and trimethoprim from a single milk sample simultaneously with no sample preparation procedure (or just one-step centrifugation).

Physicochemical Characteristic of Tea Infusion Yoghurt Inoculated with Caspian Sea Yoghurt

Application inoculum from Caspian Sea Yoghurt to produce yoghurt containing tea infusion have not been developed thoroughly, until recently. This study aimed to determine the physicochemical characteristic and sensory evaluation of tea infusion yoghurt inoculated with Caspian Sea Yoghurt. Green, white, and black tea infusion were added to UHT milk inoculated with Caspian Sea Yoghurt inoculum and incubated at 30 °C for 12 h. The yoghurt was analyzed at 0, 6, and 12 h of fermentation including pH, acidity, viscosity, colour (L, a*, b*), total polyphenol, and sensory evaluation. The result showed additional tea infusion on manufacturing yoghurt significantly affected on pH, percentage of acidity, viscosity, and colour parameter of yoghurt. During the fermentation process, the prolonged incubation time resulted in increased acidity and viscosity, while simultaneously decreased the pH value. At the end of the fermentation (at 12 h) of yoghurt with 10% tea infusion had a lower pH and a higher percentage of acidity compared to the yoghurt control. Addition of tea infusion on yoghurt has a lower viscosity than yoghurt without tea infusion at the end of the fermentation. Additional tea infusion on yoghurt affected reduced Lightness (L*) value but increased a* and b* value. The results of the present study indicate that additional tea infusion on yoghurt inoculated with Caspian Sea Yoghurt should be considered not only in terms of physicochemical and sensory during manufacturing and storage but also functional properties to improve human health.

Quantitation of furosine, furfurals, and advanced glycation end products in milk treated with pasteurization and sterilization methods applicable in China

Pasteurization and sterilization, normally carried out in milk, can induce the Maillard reaction, which can produce substances that are harmful to health. Quantitation of initial, intermediate, and advanced Maillard reaction products in milk was conducted for pasteurization (low-temperature long-time [LTLT], high-temperature short-time [HTST]) and sterilization (ultra-high temperature [UHT], in-bottle sterilization [BS]) methods. Total lysine and lactose decreased by 32.8% and 6.7% in BS milk, respectively. The generation of furosine in sterilized milk and pasteurized milk ranged from 2.5- to 5.0-fold and 1.4- to 2.8-fold higher, respectively, than those in raw milk. 5-(Hydroxymethyl)furfural increased by 4.7- and 8.4-fold in UHT and BS milk, and 2-furaldehyde (F) was not quantified in raw and LTLT milk. The concentrations of Nε-(carboxymethyl)lysine (CML) was nearly 4.4- to 6.7-fold higher than that of Nε-(carboxyethyl)lysine in the heated milk samples. CML in UHT and BS milk were around 1.4–fold and 1.6-fold higher than that in raw milk, respectively. The concentration of these Maillard reaction products in sterilized milk was significantly higher than those in raw, LTLT, and HTST milk. The results of this study could improve safety control in the dairy industry with respect to pasteurization and sterilization procedures.

Lactose oxidase: Enzymatic control of Pseudomonas to delay age gelation in UHT milk

Shelf-stable milk is consumed worldwide, and this market is expected to continue growing. One quality challenge for UHT milk is age gelation during shelf life, which is in part caused by bacterial heat-stable proteases (HSP) synthesized during the raw milk storage period before heat processing. Some Pseudomonas spp. are HSP producers, and their ability to grow well at refrigeration temperature make them important spoilage organisms for UHT processors to control. Previous studies have shown that lactose oxidase (LO), a natural and commercially available enzyme that produces hydrogen peroxide and lactobionic acid from lactose, can control bacterial growth in raw milk. In this research, we investigated the ability of LO to control HSP producer outgrowth, and thus delay age gelation in UHT milk. Six strains of Pseudomonas spp. were selected based on their ability to synthesize HSP and used as a cocktail to inoculate both raw and sterile (UHT) milk at a level of 1 × 105 cfu/mL. Groups were treated with and without LO, stored for 4 d at 6°C, and monitored for cell count and pH. Additionally, a sample from each was tested for HSP activity via particle size analysis (average effective diameter at 90° angle and 658 nm wavelength) and visual inspection on each day of the storage period. The HSP activity results were contrasted using Tukey's HSD test, which showed that in UHT milk, a LO treatment (0.12 g/L) effectively prevented gelation as compared with the control. In raw milk, however, a concentration of 0.24 g/L of LO was needed to obtain a similar effect. This test was scaled up to 19-L pilot plant batches of raw milk where they were challenged with Pseudomonas cocktail, treated with LO for 3 d, and then UHT processed. Resulting UHT milk bottles were monitored for gelation. Significant differences in particle size between the LO-treated samples and the control were observed as early as 1 mo after processing, and gelation was not detected in the LO-treated samples through 6 mo of storage. These results demonstrated that LO can be used to delay age gelation in UHT milk induced by HSP-producing Pseudomonas spp., representing an opportunity to improve quality and reduce postproduction losses in the shelf-stable milk market sector.

Analysis of consumers’ preference on taro-flavored UHT Ultra milk using conjoint method in Malang City

One of the processed milk products is Ultra Taro UHT milk. The aim of this research was to analyze Ultra Taro UHT milk’s importance level of attributes and combinations of the attributes which are preferred based on consumer preferences. This study was quantitative correlational using a questionnaire with a full profile presentation method. The study was conducted for one month, with 60 respondents determined by the purposive sampling method. Data was processed using the conjoint method. In this research, 4 product attributes were used, there are flavor with 3 levels, volume with 3 levels, fat content with 2 levels, and type of packaging with 2 levels. The results showed the level of importance value, attribute flavor with a relative value of 34.44%, volume and packaging types have similar relative value of 27.79%, and fat content with a relative value of 9.97%. The combination of attributes favored by consumers was the fifth stimuli with a total use value of 3.8283 consisting of taro balanced milk flavor attributes, 200 ml volume contents, low fat, and tetra pack packaging types. The results of the conjoint have significant correlation with the opinion of respondents with a positive Kendall Tau correlation value of 0.889.

Occurrence, exposure evaluation and risk assessment in child population for aflatoxin M1 in dairy products in Brazil

This study aimed to evaluate the risk concerning child population's health because of the occurrence of AFM1 in UHT milk, powdered milk (PM) and infant formulae (IF). Determination of AFM1 was performed in 60 samples and evaluation of the mycotoxin exposure was carried out through the determination of the estimated daily intake (EDI), whereas risk characterization was evaluated with the calculation of the risk of Hepatocellular Carcinoma (HCC) and the Margin of Exposure (MOE). AFM1 ranged from 150 to 1020 ng/kg, and all the positive samples exceeded the limits stablished by European Community. The EDI for AFM1 ranged according to the age group of the population studied (0–5 years old) from 0.828 to 2.523, 0–2.113 and 0.029–0.833 ng/kg b. w./day in UHT, PM and IF, respectively. The number of HCC cases associated with AFM1 exposure (0.0015 a 0.0045) was higher than the limit of 0.001 case/100,000. MOE values for AFM1 were 728 to 239, considerably below the security margin of 10,000. These results point to a potential risk to the health of Brazilian child population exposed to AFM1 in dairy products.

MICROBIOLOGICAL QUALITY ANALYSIS OF FERMENTED AND UHT MILK SAMPLES COLLECTED FROM DIFFERENT LOCATIONS IN INDONESIA

&#x0D; Diarrhea can occur due to food and beverage poisoning, with the highest cause being caused by infection with various bacteria, viruses, or parasites. Bacteria that can cause this disease are Escherichia coli bacteria which are known as good bacteria in the digestive tract. But the reality is that in microbiology not all types of Escherichia coli are good bacteria. Aim to find out the content and number of Escherichia coli bacteria colonies in UHT milk brands A and B as well as brand x yogurt products. Identification of Escherichia coli bacteria by the IMVIC Test method (Indole, Methyl-Red (MR) test, Voges Proskauer (VP), and Citrate), TPC (Total Plate Count), bacterial staining and microscope observation. Negative and positive results were obtained in the indole test and the methyl-red test was characterized by the formation of a red ring at the top for positive results and a yellow ring at the top for negative results, as well as negative results obtained in the Voges Proskauer test and the citrate test. Then for the results of gram staining and microscope testing the bacterial morphology was not seen. For the calculation of colonies, 45 colonies of sample A, 60 colonies of sample B, and 38 colonies of sample X. Samples containing Escherichia coli are contained in sample A of UHT milk and sample X of yogurt products and microbial contamination in samples according to SNI 2009.&#x0D; &#x0D;

FACTORS THAT AFFECT THE THERMAL STABILITY OF BOVINE MILK AND THE USE OF ALCOHOL TEST IN THE MILK INDUSTRY – A REVIEW

The dairy industry requires good quality milk with an adequate yield that does not affect the industrial process. Therefore, to produce safe food for consumers aiming to increase the shelf life of the product, the before mentioned industry makes use of heat treatment (pasteurization or UHT – Ultra-high Temperature processing). Milk must have adequate quality and high-temperature resistance; otherwise, thermal stability problems may occur. The alcohol or alizarin test is used in dairy farms to identify milk samples that present over the normal acidity and to measure their stability before being transported to the consumer market. Thus, the objective of this review was to search, in the literature, for evidence regarding the factors that interfere in the heat stability of milk and the use of the alcohol test. False-positive results are usual in samples that make use of that test, showing cases of unstable non-acid milk and putting in jeopardy the reliability of the results.