Dairy Food Processing Research Articles

ACTIVIDAD LIPOLITICA DE MICROORGANISMOS AISLADOS DE AGUAS RESIDUALES CONTAMINADAS CON GRASAS

Lipases are one of the groups of enzymes with the highest number of industrial and biotechnological applications, processing of dairy foods and oils, detergents, cosmetics, leather, pharmaceuticals, paper, production of surfactants, biodiesel and recently as a promising alternative for the treatment of wastewater contaminated with lipids. In this study, microorganisms were isolated from wastewater samples containing fats and extracellular lipase production was determined using p-nitrophenylpalmitate. From the 149 isolates obtained, 37 showed lipolytic activity and strain CCEI-1, identified as Serratia marcescens, had the highest activity at alkaline pH and at 30°C. Also degraded lipids and produced pigmentation on solid medium at pH 8,0 and 50°C. The culture supernatants of S. marcescens used to determine thermal stability at 50°C indicate that the enzyme is stable at this temperature and at alkaline pH. The enzyme was partially purified and electrophoresed (SDS-PAGE) where bands between 40 and 116 kDa were detected. The results obtained in this study indicate that the strain CCEI-1 of S. marcescens can be a possible source of thermostable lipases with industrial and biotechnological applications.

Predicting lactulose concentration in heat-treated reconstituted skim milk powder using front-face fluorescence

Industrial processing of milk and dairy foods requires heat treatment, which induces undesirable effects in milk such as protein denaturation, organoleptic and nutritional properties alteration, browning, etc. The hypothesis of the present study is that it is possible to use front-face measurement of fluorescent markers such as tryptophan, dityrosine, Maillard intermediate compounds and riboflavin as an inline, cheap, easy and fast way to evaluate lactulose formation in milk. Thus, the specific objective of this study was modeling the kinetics of lactulose formation during heat treatment of milk as well as evaluating the correlation of lactulose concentration with fluorescent markers in order to obtain prediction models of lactulose concentration in heat-treated milk based on front-face fluorescence.Three replicates of the study were performed at three different temperatures (80, 90 and 100 °C) and six different times (0, 10, 15, 30, 45 and 60 min). Standard, low-heat, spray-dried skim milk powder, supplied by Chr. Hansen SL (Barcelona, Spain) was reconstituted at 12% and used in all trials to ensure consistency among the various experimental trials.Lactulose concentration was significantly correlated (P < 0.001) with fluorescence intensity of different markers such as maximum intensity and maximum emission wavelength of tryptophan as well as the fluorescence intensity of riboflavin. Fluorescence changes associated to thermal treatment of milk were characterized and a series of fluorescent markers were identified as predictors allowing prediction of lactulose concentration with an R2 of 0.91 at a temperature of 90 °C.

A simple model for estimating the concentrations of natural estrogens in raw wastewater

This study provides a tool for predicting the concentrations of the natural estrogens (NEs) estrone, 17β-estradiol and estriol in raw wastewater (WW). Data characterizing the biochemical oxygen demand (BOD), NE concentrations, and discharges of raw sewage to wastewater treatment plants (WWTPs) were collected from various publications and used in the model formulation. A strong correlation was found between the log transformed BOD and the log transformed estrone load (r2=0.84, n=61), the log transformed 17β-estradiol load (r2=0.89, n=52) and the log transformed estriol load (r2=0.80, n=40). The models are reasonably accurate when compared to the measured concentrations and slightly better than previous modeling efforts. The relative amounts of data falling within ±50% error were 67% for estrone, 63% for 17β-estradiol, and 55% for estriol. Because the model was developed from a wide array of WWTPs from five continents, it is universal and can be used for projecting concentrations of NEs from a wide range of mixed domestic and industrial sources, but may be less precise when sources contain high levels of NEs or BOD (e.g., WW from dairy farms and food processing plants). The model is expected to improve our ability to predict the fate of NEs in WWTPs and in the receiving environment, which currently relies on estimating the concentrations of NEs in raw wastewater. Its application is especially valuable since direct measurement of NEs in raw WW is expensive and practically impossible in many developing countries due to the lack of expertise and funds.

Developing a Contemporary Dairy Foods Extension Program: A Training and Technical Resource Needs Assessment of Pennsylvania Dairy Foods Processors

Growth in the dairy industry and the passage of the Food Safety Modernization Act have renewed interest in dairy foods processing extension positions. A needs assessment survey was sent to Pennsylvania dairy processors and raw milk providers to guide priorities for a dairy foods extension program. The successful development and delivery of technical resources will require tailoring to specific segments of the industry. Priority training topics are good manufacturing practices, sanitation, and food safety regulations. Larger processors preferred on-line resources and other processors preferred face-to-face workshops. An informational newsletter and website were also of great interest.

WASTEWATER MANAGEMENT IN FOOD PROCESSING ENTERPRISES – A CASE STUDY OF THE CIECHANÓW DAIRY COOPERATIVE

The paper reports on wastewater management in food processing enterprises, using the Ciechanow Dairy Cooperative as an example. The efficiency of preliminary treatment of wastewater entering the municipal sewerage system was evaluated using basic pollution indices for wastewater pre-treated in the process of chemical neutralisation as well as results of physical and chemical analyses of raw wastewater from fromage fraise and cottage cheese production lines. The number of exceedances of permissible values of pollution indices in pre-treated wastewater was determined based on values set in the water legal permits issued by the relevant authority. Pre-treated wastewater entering the municipal sewerage system met the standards for permissible wastewater pollution indicators excluding BOD5 (biochemical oxygen demand) and COD (chemical oxygen demand). Physical and chemical analysis was performed of total raw wastewater and wastewater discharged from fromage fraise and cottage cheese production lines. Pollution indicators (COD, total nitrogen, orthophosphates, total suspensions, fats, pH) had high values but they remained within the ranges typical for dairy food processing.

Ethanol production from agroindustrial biomass using a crude enzyme complex produced by Aspergillus niger

This study investigates ethanol production from simultaneous fermentation and saccharification (SFS) and separated hydrolysis and fermentation (SHS) using enzyme complexes produced by Aspergillus niger strains (ATCC 16404, ATCC 1057, ATCC 9029). The enzyme complexes were produced by solid-state fermentation (SSF) on inexpensive and readily available agroindustrial products: rice byproduct (composed of AFEX-treated rice rust and rice bran), whey and sugarcane bagasse. The ethanol was produced by Saccharomyces cerevisiae Y904 using whey and rice byproduct as the substrate and the enzyme complex produced by A. niger. The best result for solid-state fermentation (40 U/g of dry substrate, A. niger ATCC 16404) was obtained in a 0.5 L rotating drum bioreactor at 40 °C filled half filled with solid biomass composed of rice byproduct (86% wt/wt), whey (12% wt/wt) and CaCl2 (2.0% wt/wt). The best result for ethanol fermentation (11.7 g/L of ethanol) was obtained after 12 h of SFS at pH 4.5 and 35 °C. A comparative study of ethanol production by Trichoderma reesei CCT 2768 and A. niger ATCC 16404 complexes under the same optimised SFS and SSF conditions was also performed, revealing that ethanol production by the A. niger enzyme complex was 2.25 times higher than that by T. reesei. These findings suggest that the ethanol production using crude enzymatic complexes produced by A. niger and agroindustrial biomass described in this paper is very promising in terms of disposal of the whey produced by cheese-making and other dairy food processing.

Supply Chain Management and Network Distribution of Safal Market

Supply Chain Management consists of all parties involved directly or indirectly in fulfilling a customer request. The supply chain not only includes the producers and suppliers but also transporters, warehouses, retailers, and customer themselves within each organization such as producer, the supply chain includes all function involved in receiving and filling consumer request. Improving the post harvest management means an overall improvement in the per unit productivity. In last one decade various marketing models have been initiated, Mother Dairy cooperatives in fresh fruits and vegetables under the name of SAFAL, further their alternative whole sale market-SAFAL Market. The traditional Indian markets have a non-existent infrastructure of packing, grading, sorting and cold storages. The commission agents and traders dominate the supply chain and are the major price setters, thus most of the times farmers are dependent on them for credit. Farmers are not aware of the price setting mechanisms as the system is not transparent and thus don't have any incentive to produce efficiently. The National Dairy Development Board (NDDB) has started the Fruit and Vegetable Unit of SAFAL at Delhi, which is one of the first fruit and vegetable retail chains set up as a part of the Mother Dairy Foods Processing Ltd. The retail unit provided a direct link between fruit and vegetable growers and consumers. The other initiative was a fruit processing Plant of SAFAL at Mumbai, a 100 per cent export-oriented unit, which capitalizes NDDB's food processing strength. NDDB has set up an alternate system of wholesale markets in Bangalore as a pilot project. The initiative is named as SAFAL Market and is initiated to fine-tune horticultural growth in India, by a shift in their earlier retail chain model to a wholesale market concept.This paper addresses the Supply Chain Management as it concerns with 'integration' of firms in the face of coordinating materials and information flows within a procurement-production-distribution network in order to attain the Safal Market goals with special reference to fruits and vegetables.

Supply Chain Management and Network Distribution of Safal Market

Supply Chain Management consists of all parties involved directly or indirectly in fulfilling a customer request. The supply chain not only includes the producers and suppliers but also transporters, warehouses, retailers, and customer themselves within each organization such as producer, the supply chain includes all function involved in receiving and filling consumer request. Improving the post harvest management means an overall improvement in the per unit productivity. In last one decade various marketing models have been initiated, Mother Dairy cooperatives in fresh fruits and vegetables under the name of SAFAL, further their alternative whole sale market-SAFAL Market. The traditional Indian markets have a non-existent infrastructure of packing, grading, sorting and cold storages. The commission agents and traders dominate the supply chain and are the major price setters, thus most of the times farmers are dependent on them for credit. Farmers are not aware of the price setting mechanisms as the system is not transparent and thus don't have any incentive to produce efficiently. The National Dairy Development Board (NDDB) has started the Fruit and Vegetable Unit of SAFAL at Delhi, which is one of the first fruit and vegetable retail chains set up as a part of the Mother Dairy Foods Processing Ltd. The retail unit provided a direct link between fruit and vegetable growers and consumers. The other initiative was a fruit processing Plant of SAFAL at Mumbai, a 100 per cent export-oriented unit, which capitalizes NDDB's food processing strength. NDDB has set up an alternate system of wholesale markets in Bangalore as a pilot project. The initiative is named as SAFAL Market and is initiated to fine-tune horticultural growth in India, by a shift in their earlier retail chain model to a wholesale market concept.This paper addresses the Supply Chain Management as it concerns with 'integration' of firms in the face of coordinating materials and information flows within a procurement-production-distribution network in order to attain the Safal Market goals with special reference to fruits and vegetables.

EFFICACY OF INFRARED HEAT TREATMENT FOR INACTIVATION OF STAPHYLOCOCCUS AUREUS IN MILK

ABSTRACT The efficacy of infrared (IR) heating for inactivation of Staphylococcus aureus, a pathogenic microorganism, in milk was studied to investigate the potential of this technology for milk processing. S. aureus population was reduced from 0.10 to 8.41 log10 cfu/mL, depending upon the treatment conditions. The effects of IR lamp temperatures (536 and 619C), volumes of treated milk samples (3, 5 and 7 mL) and treatment times (1, 2 and 4 min) on the lethality of targeted microbes were found to be statistically significant (P &lt; 0.05). Complete inactivation of S. aureus was obtained in two cases within 4 min at a 619C lamp temperature, resulting in 8.41 log10 cfu/mL reduction. Enrichment resulted in growth as some of the injured cells were able to repair. Further investigation of IR heating for longer treatment times (&gt;4 min) indicated that there was no growth observed following the enrichment in most cases for treatment at the lamp temperature of 619C. The results demonstrated that IR heating has a potential for effective inactivation of S. aureus in milk.To ensure the sterility efficacy, the heating patterns of milk samples under IR radiation were simulated using computational fluid dynamics codes in three dimensions with user‐defined functions for radiative internal energy source terms. The predicted temperature values were in good agreement with the experimental data with the maximum prediction error of 5.2C. Further optimization of the process parameters, i.e., temperature and heating time, using the developed model is expected to ensure that even underprocessed food components will receive desirable doses of lethality, which can result in a commercially successful milk pasteurization method.PRACTICAL APPLICATIONSInfrared (IR) heating has been used in the food industry as a heating or drying method because of several advantages such as minimal deterioration in food quality, faster heating and higher energy efficiency. IR heating can effectively inactivate pathogenic microorganisms in dairy products compared with conventional heating. IR heating cannot only effectively inactivate pathogenic microorganisms in dairy foods, but also preserve the quality. Furthermore, IR heating is found to be cost effective as it can reduce the energy consumption up to 44% for various food products compared with conventional heating. Results from this study could provide a basis for the application of IR heat treatment for dairy food processing. Further investigation on sensory and quality changes during IR heating can shed light on the efficacy of this process and may provide a potential novel pasteurization method for the dairy industry.

Identification of Novel Phosphopeptides After Simulated Digestion of αs2-casein by Tandem Mass Spectrometry

Casein phosphopeptides (CPPs) are encrypted in αs1-, αs2-and β-casein (CN) and can be released by in vitro, in vivohydrolysis or food processing of dairy foods. Bovine αs2-CN contains two cluster sequences of anionic phosphoseryl and glutamyl residues SpSpSpEE in its structure (residues 8–12 and 56–63), which can modulate mineral bioavailability. In this study αs2-casein (αs2-CN) was subjected to simulated gastrointestinal digestion. CPPs released were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). Six novel αs2-CN derived CPPs, Three of them (αs2-CN(54–87)4P,αs2-CN(24–70)4P and αs2-CN(14–73)5P) with the mineral binding cluster sequence SpSpSpEE were identified and characterised. CPPs from αs2-CN identified in this study resist simulated gastrointestinal digestion. As the molecular weights of these CPPs are approx. 2,165–7,112Da, they could be absorbed by intestinal cells. Consequently, these αs2-CN derived CPPs could be promising candidates for incorporation to mineral fortified foods as functional ingredients.

Major Advances in Concentrated and Dry Milk Products, Cheese, and Milk Fat-Based Spreads

Advances in dairy foods and dairy foods processing since 1981 have influenced consumers and processors of dairy products. Consumer benefits include dairy products with enhanced nutrition and product functionality for specific applications. Processors convert raw milk to finished product with improved efficiencies and have developed processing technologies to improve traditional products and to introduce new products for expanding the dairy foods market. Membrane processing evolved from a laboratory technique to a major industrial process for milk and whey processing. Ultra-filtration and reverse osmosis have been used extensively in fractionation of milk and whey components. Advances in cheese manufacturing methods have included mechanization of the making process. Membrane processing has allowed uniform composition of the cheese milk and starter cultures have become more predictable. Cheese vats have become larger and enclosed as well as computer controlled. Researchers have learned to control many of the functional properties of cheese by understanding the role of fat and calcium distribution, as bound or unbound, in the cheese matrix. Processed cheese (cheese, foods, spreads, and products) maintain their importance in the industry as many product types can be produced to meet market needs and provide stable products for an extended shelf life. Cheese delivers concentrated nutrients of milk and bio-active peptides to consumers. The technologies for the production of concentrated and dried milk and whey products have not changed greatly in the last 25 yr. The size and efficiencies of the equipment have increased. Use of reverse osmosis in place of vacuum condensing has been proposed. Modifying the fatty acid composition of milkfat to alter the nutritional and functional properties of dairy spread has been a focus of research in the last 2 decades. Conjugated linoleic acid, which can be increased in milkfat by alteration of the cow's diet, has been reported to have anticancer, anti-atherogenic, antidiabetic, and antiobesity effects for human health. Separating milk fat into fractions has been accomplished to provide specific fractions to improve butter spreadability, modulate chocolate meltability, and provide texture for low-fat cheeses.

乳牛ふん尿と有機性廃棄物による混合メタン発酵消化液の秋蒔き小麦（ホクシン）への施用

The purpose of this study was to evaluate the effect of anerobically co-digested dairy manure and food processing wastes as an organic fertilizer, and to investigate the changes in soil nitrogen and grain yield of winter wheat (Hokushin) comparing digested dairy manure with chemical fertilizer.By the incubation test, it was clear that the NH4-N was almost converted into the NO3-N for four weeks. Over the period of 101 days, 15% of inorganic N was accumulated in the soil.Between grain yields where co-digested dairy manure and chemical fertilizer were applied, there were no significant difference, but protein contents in grain were higher in co-digested manure applied than chemical fertilizer one (p<0.05).

Glass Transitions and Crystallization in Milk Powders

Glass transition temperatures were determined for dehydrated milk products with various water contents and water activities, and state diagrams were established. Crystallization behavior was studied with milk powders stored at various relative humidities. Glass transition temperatures of milk powders containing lactose were close to those of pure lactose. Skim milk powder with hydrolyzed lactose had considerably lower glass transition temperatures. Glass transition temperatures decreased as water content increased. The critical water content and water activity for stability at 24°C were predicted using data on glass transition temperature and water sorption. Lactose and milk powders containing lactose had the same critical water activity or storage relative humidity, but slightly different critical water contents. The critical values for skim milk with hydrolyzed lactose were much lower than those for regular milk powders. Loss of adsorbed water, indicating lactose crystallization, was observed in milk powders stored above the critical relative humidity. Glass transition temperatures and state diagrams can be used to evaluate changes during processing and storage of dairy foods.

Evaluation of dairy food processing wash water solids as a protein source: II. Microbial protein synthesis, duodenal nitrogen flow, and small intestinal amino acid disappearance

Twelve ruminally, duodenally, and ileally-cannulated Hereford heifers (average initial BW 313 +/- 20 kg) were used in a replicated experiment to evaluate dairy food processing wash water solids (WWS) as a protein source. Heifers were fed 2.8 kg of chopped (7.6 cm) hay and one of three supplements (1.5 kg/d, DM basis). Supplements were formulated to be similar in energy and contained 1.0 (control), 23.2 (WWS), and 21.6% (soybean meal; SBM) CP on an OM basis. Total N and nonammonia N entering the duodenum (g/d) were greater (P less than .10) for heifers fed WWS and SBM supplements than for controls. Bacterial N flow (g/d) at the duodenum was less (P less than .10) for controls (43.9) than for WWS- (63.9) and SBM- (69.9) supplemented heifers. Feed escape N (g/d) was greater (P less than .10) for WWS-fed heifers than for those fed SBM (32.1 vs 20.7 g/d, respectively). Total tract N digestion (g/d) was greatest (P less than .10) for SBM, intermediate for WWS, and least for control heifers. Microbial protein synthesis (g/kg of OM intake) was enhanced (P less than .10) by WWS and SBM supplementation, but efficiency of synthesis (g/kg of OM fermented) did not differ among treatments. Essential amino acid (AA) disappearance in the small intestine (g/d) was less (P less than .10) for control than for the other two treatments. Nonessential AA disappearance was greatest (P less than .10) for the WWS and least (P less than .10) for the control treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of dairy food processing wash water solids as a protein source: III. Nitrogen utilization by heifers fed medium-concentrate diets2

Eight multicannulated heifers (average BW 415 +/- 34 kg) were used in a replicated 4 x 4 Latin square to evaluate fluid milk processing wash water solids (WWS) as a dietary N source. Heifers were fed corn/cottonseed hull-based diets containing soybean meal (control, 0% WWS N) or WWS replacing soybean meal at 33, 67, or 100% of supplemental dietary N. Total tract and ruminal DM and OM digestibilities decreased linearly or cubically (P less than .05) as dietary WWS N increased. Total ruminal VFA concentration (P less than .05) and propionic acid molar proportion (P less than .10) were greater in heifers fed 0 vs 100% WWS N. Heifers fed 0% WWS N had the greatest (P less than .05) ruminal ammonia concentration at all sampling times. Dietary WWS did not affect (P greater than .10) ruminal pH, fluid dilution rate, fluid flow, fluid volume, or turnover time. Total tract N digestibility decreased quadratically (P less than .10) with increasing WWS N in the diet. Supplemental WWS N did not affect (P greater than .10) flow of duodenal ammonia N or bacterial N, or efficiency of microbial N synthesis. Diets containing WWS N resulted in a cubic increase (P less than .10) in duodenal flow of essential amino acids compared with 0% WWS N; however, there were no differences in small intestinal amino acid disappearance. Data indicate that WWS can replace 33% of the soybean meal N in a corn/cottonseed hull-based diet without decreasing ruminal fermentation, fluid digesta kinetics, microbial efficiency, or small intestinal amino acid utilization.

Evaluation of dairy food processing wash water solids as a protein source: I. Forage intake, animal performance, ruminal fermentation, and site of digestion in heifers fed medium-quality hay.

Twelve ruminally, duodenally, and ileally cannulated (average initial BW 313 +/- 20 kg) and 27 intact Hereford heifers (average initial BW 256 +/- 17 kg) were used in two experiments to evaluate dairy food wash water solids (WWS) as a protein source in medium-quality hay diets. Heifers received a basal diet of orchardgrass hay (7.4% CP) and were assigned to one of three supplement treatments: control (C; .9% CP), WWS (18.8% CP)-, and soybean meal (SBM; 19.1% CP)-based supplements (fed at 1.5 kg of DM/d). Supplements were formulated to have similar ME concentrations. Ruminal ammonia concentrations were greater (P less than .10) for WWS- and SBM-supplemented heifers than for C heifers at most sampling times. Moreover, WWS and SBM increased (P less than .10) total VFA (mM) and acetate (mol/100 mol) and lowered propionate (mol/100 mol) at several sampling times. Ruminal fluid volume (liters) was unchanged (P greater than .10) by treatment; however, fluid dilution and flow rate (liters/h) were less (P less than .10) in C heifers than in heifers fed SBM or WWS supplements. Wash water solids and SBM supplementation increased (P less than .10) OM, NDF, and ADF digestibilities compared with C heifers. Feeding WWS and SBM supplements increased BW at 84 d (P less than .10) compared with C-supplemented heifers. Forage intake at 54 and 84 d by heifers supplemented with SBM or WWS was greater (P less than .10) than by C heifers. Control-supplemented heifers had the least, WWS intermediate, and SBM the greatest ADG at 84 d (P less than .10; .14 vs .35 vs .48 kg/d, respectively). These data indicate that WWS may be used as a protein source without serious adverse effects in heifers consuming medium-quality hay for 84 d.

RECRUITING PERSONNEL FOR A DYNAMIC INDUSTRY IN THE SOARING SEVENTIES

The dairy industry and regulatory agencies are suffering from a severe manpower shortage. Recent surveys show that enrollment in agricultural colleges is up, but that the dairy science and regulatory-oriented curricula are not drawing their share of the new student crop.Suggestions for rectifying these manpower shortages include: changing the image of agriculture in general; involving regulatory and dairy industry people in a one to one career guidance situation with potential recruits; increasing incomes and inducements for dairy- and regulatory-related professions; and establishing innovative training programs and curricula to interest a wider segment of our young people in dairy foods processing and regulatory professions.

EFFECT OF SOLUTE CONCENTRATION AND PRE-SOIL INTERACTION ON THE MICROFLORA OF DAIRY ORIGIN ON STAINLESS STEEL SURFACES

Use of modern dairy food processing equipment creates a complex microenvironment. Closed systems reduce air drying. The rate and extent of drying are dependent on temperature and humidity of the environment. These factors were studied to determine their impact on the microflora of films of milk on stainless steel surfaces. An ecosystem was established to simulate dairy food equipment by using 1cm2 pieces of stainless steel in controlled humidity chambers. Presoiling water loss from a film of milk, and solute concentration were studied to determine their influence on the fate of the microflora. Temperature and humidity of the atmosphere influenced the rate of moisture loss from films. Pre-soiling reduced the rate of water loss from films of milk sufficiently to allow bacterial growth at 12–80% relative humidity (RH). Results indicate bacteria can grow in a film placed in humidities well below the 95% RH limit previously projected. Apparently the substrate is influenced by interaction of the milk film and the stainless steel surface.