FLAVOR AND SHELF LIFE OF FLUID MILK1,2

1974 ◽  
Vol 37 (6) ◽  
pp. 346-349 ◽  
Author(s):  
Sidney E. Barnard

Today's consumer determines the acceptance of milk by flavor and shelf life. Rancid, oxidized, and strong feed tastes of raw milk need to be eliminated. To prevent rancid and psychrotrophic flavor development, milk should be processed within 24 h of collection. Hot water sterilization of processing and filling equipment is essential. Product temperatures below 40 F at the filler extend shelf life. Proper handling during delivery and in stores is necessary to maintain good taste and keeping quality. Temperatures below 40 F, minimal fluorescent light and daylight exposure, and proper rotation are the key factors. Containers vary in their ability to protect the flavor and change in milk composition. Holding quality programs of 14 days at 45 F should be adopted by industry. Ten-day coding or open dating should be practiced by all processors. Regulatory agencies need to permit tests which will indicate shelf life. More emphasis must be placed on factors which determine consumer acceptability. These are flavor and shelf life.

2020 ◽  
Vol 16 (8) ◽  
pp. 1183-1195
Author(s):  
Prasad Rasane ◽  
Nitya Sharma ◽  
Sana Fatma ◽  
Sawinder Kaur ◽  
Alok Jha ◽  
...  

Background: Background: Milk forms an integral part of the human diet from the nutritional point of view. Besides nutrition, it has also unique functional properties which are harnessed by the industry for numerous uses. Being highly perishable specific techniques are required to minimize the losses during processing and adequate preservation of this precious commodity. In the U.S. and many other parts of the world, the traditional pasteurization of milk requires a minimum heat treatment of 72ºC for 15 seconds with subsequent refrigeration. However, the advent of Ultra High Temperature (UHT) treatment of milk has added a new dimension to the marketing of liquid milk in urban as well as remote areas without the requirement of cold chain management. The distinctive feature of UHT processed milk is that it is commercially-sterile-not pasteurized and so has long shelf life at room temperature. UHT milk, also known as long-life milk, is emerging as an attractive commercial alternative offering a hygienic product of unmatched quality, which can be bought anywhere, at any time and in any quantity. The present review will discuss numerous aspects of UHT processing of milk with reference to historical significance, fundamental principle, various systems used and prerequisites, type of exchangers used, fouling and other defects in system, chemical and microbiological effect of the treatment, its effect on nutritional components, organoleptic quality of milk and the advantage and involved challenges of the process. Conclusion: Raw milk is easily contaminated with pathogens and microbes and hence its consumption of raw milk is associated with certain ill health effects. Therefore, heating milk before consumption is strongly suggested. Thus, UHT treatment of milk is done to ensure microbial safety and also to extend the shelf life of this highly perishable commodity. Heating milk at such a high temperature is often associated with the change of organoleptic properties like change in flavor or cooked flavor, rancidity due to microbes or acid flavor, etc. But UHT treatment does not substantially decrease the nutritional value or any other benefits of milk.


Horticulturae ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 19 ◽  
Author(s):  
Daniel Chalupowicz ◽  
Sharon Alkalai-Tuvia ◽  
Merav Zaaroor-Presman ◽  
Elazar Fallik

Acorn squash fruits (Cucurbita pepo L.) are very sweet and are an excellent source of nutrients and vitamins. Very little information is available about their optimal storage temperature or how to extend their shelf life. The present goal was to elucidate the best storage temperature of this fruit, and to evaluate hot water rinsing and brushing (HWRB) technology to maintain fruit quality for several months. The optimal storage temperature was found to be 15 °C. However, treating the fruits with HWRB at 54 °C for 15 s and then storing them at 15 °C significantly maintained fruit quality for 3.5 months, as indicated by higher fruit firmness, lower decay incidence, and improved retention of green skin color.


1975 ◽  
Vol 38 (7) ◽  
pp. 388-392 ◽  
Author(s):  
A. P. HANSEN ◽  
L. G. TURNER ◽  
L. W. AURAND

Homogenized milk packaged in polyethylene containers exposed to fluorescent lights showed flavor and vitamin deterioration. Off-flavor development began within 2 to 4 h after exposure to a lighting system simulating commercial display cases. Detection of light-induced flavor was slight, medium, and strong after 4, 7 and 24 h of exposure. Decreases in riboflavin and ascorbic acid were directly proportional to the amount of light exposure. Various types of colored lamps and lamp filters were tested to prevent this off-flavor and vitamin degradation in milk. Yellow lamps or yellow and green filters protected milk from off-flavor development for 30 to 40 h. It is evident that light-induced off-flavors and vitamin destruction in fluid milk packaged in polyethylene containers can be reduced by colored lamps and lamp filters.


1996 ◽  
Vol 79 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Dominique Lefier ◽  
Remy Grappin ◽  
Sylvie Pochet

Abstract The accuracy of fat, crude protein (CP), true protein (TP), and lactose determinations of raw milk by Fourier transform infrared (FTIR) spectroscopy and by analysis with a conventional filter-based milk analyzer was assessed in 6 trials performed over a 10-month period. At each trial, 30 bulk milk samples collected from 15 European countries and 11 reconstituted milks made from raw milk components were analyzed. When calibrations were performed with reconstituted milks at each trial, accuracy standard deviations for fat, CP, TP, and lactose were, respectively, 0.050,0.048,0.035, and 0.076 g/100 g for the filter instrument and 0.047, 0.046,0.042, and 0.065 g/100 g for the FTIR instrument. When a single calibration was made instead of calibrations at each trial, accuracy standard deviations increased for the filter instrument to 0.130, 0.119,0.121, and 0.083 for fat, CP, TP, and lactose, respectively, and for the FTIR instrument to 0.082, 0.053,0.044, and 0.084 g/100 g. Because the FTIR instrument provides more spectral information related to milk composition than does the filter instrument, single-calibration FTIR analysis of milk samples collected in different seasons is more accurate. Using reconstituted milks, prepared such that there is no correlation between fat, CP, and lactose, provides a more robust calibration than using genuine bulk milk, especially when milks with unusual composition are analyzed.


2016 ◽  
Vol 2 (2) ◽  
pp. 266-273
Author(s):  
ABM Kawsar Ahmed ◽  
Md Rezwanul Habib ◽  
Samia Afrin ◽  
Mohammad Ashiqul Islam ◽  
Md Harun Ur Rashid

The work has been designed to investigate the utilization of milk for consumption of fluid milk and milk products, their distribution pattern, pricing, shelf life and consumer’s preference of Mymensingh municipality in Bangladesh. The study was based on milk and milk products and data were collected from the selected sweetmeat shops by direct interview, of which 20 samples were collected from sweetmeat shops and 7 from goalas. Both tabular and statistical methods were used for collected data analysis. Shopkeepers of different sweetmeat shops received raw milk from farmers (52.6%) and goalas (47.4%) and the highest amount of whole milk was required in per unit production of rasomalai (21%) and ghee (18%) whereas the lowest amount in chomchom (9%). Milk products prices were not remained same throughout the year in this municipality due to fluctuation of raw milk availability and their price. Eid, Puja festivals and other educational activities results that may increase milk products selling especially rasogolla and kalojam. Research findings also showed non-significant difference in case of pricing, distribution pattern, shelf life and selling of milk and milk products following sweetmeats.Asian J. Med. Biol. Res. June 2016, 2(2): 266-273


2018 ◽  
Vol 39 (5) ◽  
pp. 2049 ◽  
Author(s):  
José Carlos Ribeiro Júnior ◽  
Ronaldo Tamanini ◽  
André Luís Martinez de Oliveira ◽  
Juliane Ribeiro ◽  
Vanerli Beloti

Aerobic bacterial spores are an important group of microorganisms in raw milk. These microbes are thermoduric, whereas the vegetative forms are thermophilic, thermoduric and psychrotrophic and reduce the shelf life of pasteurized milk. In Brazil, there are a lack of studies on the load of aerobic spores in raw milk; thus, little is known about the spoilage activity of these organisms. The aim the present study was to quantify the aerobic spores in Brazilian refrigerated raw milk of dairy region of Castro, Paraná state, assess the potential proteolytic and/or lipolytic isolates and identify the microorganisms derived from the germination. Twenty milk samples were evaluated, and the aerobic spore count was performed after plating the samples following heat treatment at 80°C for 12 min. The activity proteolytic and lipolytic isolates were evaluated through subculture on milk agar and tributyrin agar, respectively, and these microorganisms were identified using partial 16S rRNA gene sequences that were compared through GenBank. The aerobic spore counts ranged from 1 to 3.7 log CFU.mL-1, with a mean of 1.75 (± 0.59) log CFU.mL-1. After spore germination, 137 aerobic bacterial isolates were obtained, 40 of which (29.2%) showed milk spoilage activity. Among these, 31 isolates (77.5%) were proteolytic and lipolytic, seven isolates (17.5%) were exclusively lipolytic and two isolates (5%) were only proteolytic. Based on the 16S rRNA gene analysis, Bacillus licheniformis (55%), Bacillus spp. (27.5%), Paenibacillus spp. (7.5%), Bacillus pumilus (5%), Bacillus circulans (2.5%) and Brevibacillus spp. (2.5%) were identified. Studies of Brazilian raw milk microbiota have not yet described B. circulans which are frequently detected in milk from other countries. Among the 22 B. licheniformis isolates, 21 microbes (95.5%) showed proteolytic and lipolytic activity, and one isolate (4.5%) exhibited only proteolytic activity. The two B. pumilus isolates were proteolytic and lipolytic, whereas the B. circulans isolate was only lipolytic. Among the 11 Bacillus spp. isolates, eight isolates (72.7%) were proteolytic and lipolytic, one isolate (9.1%) was proteolytic and the other two isolates (18.2%) were lipolytic. The three Paenibacillus spp. and Brevibacillus spp. isolates were primarily lipolytic. Therefore, to extend the shelf life of pasteurized milk, preventive measures must be adopted to reduce contamination with spores because one-third of these microorganisms exhibited proteolytic and/or lipolytic activity.


2013 ◽  
Vol 27 ◽  
pp. 42-47 ◽  
Author(s):  
Md Nurul Amin ◽  
Md Mosharraf Hossain

For reducing the post-harvest loss and extension of shelf-life of banana, it is treated with fungicide or combination of fungicide and hot-water treatment. A study was conducted for developing a method to control post-harvest diseases and extension of shelf-life of banana through non-chemical method of hot water treatment. The best treatment combination was found at 53 °C for 9 minutes. Shelf-lives of BARI Kola 1 and Sabri Kola treated with hot water increased by 26 and 27.5%, respectively against untreated fruits. Post-harvest loss (decay and crown rot) of these varieties was reduced, respectively by 95% and 70% against untreated fruits. Firmness of treated fruits for both varieties was found higher than that of untreated fruits during ripening. Total soluble solid, total sugar, acidity and ?-carotene of treated fruits of these varieties increased over untreated fruits. The pH and vitamin C of treated bananas decreased over untreated fruits during ripening. DOI: http://dx.doi.org/10.3329/jce.v27i1.15857 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 1, June 2012: 42-47


2019 ◽  
Vol 52 ◽  
pp. 325-333 ◽  
Author(s):  
Alexandros Ch. Stratakos ◽  
Elena S. Inguglia ◽  
Mark Linton ◽  
Joan Tollerton ◽  
Liam Murphy ◽  
...  

2019 ◽  
Vol 40 (4) ◽  
pp. 1469
Author(s):  
José Carlos Ribeiro Júnior ◽  
Aline Marangon de Oliveira ◽  
Fernando Godoi Silva ◽  
Lorena Natalino Haber Garcia ◽  
Cátia Maria de Oliveira Lobo ◽  
...  

The dairy industry strives to produce high quality products with high nutritional value as well as to meet the legal standards for longer shelf life. However, these goals are made unfeasible by the poor quality of raw milk produced in some regions of Brazil. Others Brazilian dairy regions, however, already succeed in producing milk with low microbial counts, such as the municipality of Castro, Paraná state, designated as the ‘Brazilian dairy capital’. In order to evaluate the effect of raw milk quality on microbial counts during the shelf life of pasteurized milk, samples were collected from two dairy regions of Paraná: the northern and Castro region, characterized by milk production with high and low microbiological counts, respectively. Samples were experimentally pasteurized and the total microorganism counts were analyzed for 18 days at 7°C, using the Brazilian standard microbiological count limit for pasteurized milk (8 x 104 CFU/mL) as the end of the shelf life. Low microbiological counts in raw milk (Castro) resulted in significantly lower counts shortly after pasteurization and over the entire shelf life, meeting the pasteurized milk standard for 18 days. The temporal evolution in the counts over 18 days for the milks of high and low microbiological count was similar; however, the disparity between the absolute counts between the regions was significant (p < 0.05). Of the milk samples from northern Paraná, four (44.4%) already had counts higher than that of the legislative limit for pasteurized milk immediately after pasteurization. The others (five) reached the maximum microbiological count limit for pasteurized milk on the 6th day after pasteurization. In contrast, the milk from the Castro region remained below the limit throughout the analysis period. Thus, it can be stated that the microbiological quality of raw milk is directly related to the initial count of microorganisms after pasteurization, and that pasteurized milk produced from raw milk with low microbiological counts complies with the Brazilian legislation for 18 days following thermal processing.


2002 ◽  
Vol 56 (5) ◽  
pp. 599-604 ◽  
Author(s):  
Young-Ah Woo ◽  
Yoko Terazawa ◽  
Jie Yu Chen ◽  
Chie Iyo ◽  
Fuminori Terada ◽  
...  

A new measurement unit, the MilkSpec-1, has been developed to determine rapidly and nondestructively the content of fat, lactose, and protein in raw milk using near-infrared transmittance spectroscopy. The spectral range over 700 to 1100 nm was used. This unit was designed for general glass test tubes, 12 mm in diameter and 10 mL in volume. Al2O3 with a thickness of 2.5 mm was found to be optimum as a reference for acquiring the milk spectrum for this measurement. The NIR transmittance spectra of milk were acquired from raw milk samples without homogenization. The calibration model was developed and predicted by using a partial least-squares (PLS) algorithm. In order to reduce the scattering effect due to fat globules and casein micelles in NIR transmittance spectra, multiplicative scatter correction (MSC) and/or second derivative treatment were performed. MSC treatment proved to be useful for the development of calibration models for fat and protein. This study resulted in low standard errors of prediction (SEP), with 0.06, 0.10, and 0.10% for fat, lactose, and protein, respectively. It is shown that accurate, rapid, and nondestructive determination of milk composition could be successfully performed by using the MilkSpec-1, presenting the potential use of this method for real-time on-line monitoring in a milking process.


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