New process for the production of permeate powders without spray dryer

An innovative process scheme for the production of dairy permeate powders was tested at the pilot scale. It includes: (i) overconcentration of the permeate concentrate from 60 to 80% w/w dry matter (DM) content; (ii) granulation of the overconcentrate with powder up to 88% DM; and (iii) drying of the granules up to 97% DM.The quality of the resulting powder was comparable to a standard powder produced using conventional technologies. Furthermore, considering energy required for water removal, the new process led to significant savings: they were estimated in the range of 10.7 to 23.5% and up to 32% when taking into account the whole production process or the drying step alone, respectively

Nanofiltration of lactic acid whey: A process to improve the dryability and the quality of powder

Nanofiltration of lactic acid whey: A process to improve the dryability and the quality of powder. 6. European Drying Conference: EuroDrying 201

The Nutrinet-Santé Study: a web-based prospective study on the relationship between nutrition and health and determinants of dietary patterns and nutritional status

<p>Abstract</p> <p>Background</p> <p>Nutrition-related chronic diseases such as cardiovascular diseases and cancer are of multiple origin, and may be due to genetic, biologic, behavioural and environmental factors. In order to detangle the specific role of nutritional factors, very large population sample cohort studies comprising precisely measured dietary intake and all necessary information for accurately assessing potential confounding factors are needed. Widespread use of internet is an opportunity to gradually collect huge amounts of data from a large sample of volunteers that can be automatically verified and processed. The objectives of the NutriNet-Santé study are: 1) to investigate the relationship between nutrition (nutrients, foods, dietary patterns, physical activity), mortality and health outcomes; and 2) to examine the determinants of dietary patterns and nutritional status (sociological, economic, cultural, biological, cognitive, perceptions, preferences, etc.), using a web-based approach.</p> <p>Methods/design</p> <p>Our web-based prospective cohort study is being conducted for a scheduled follow-up of 10 years. Using a dedicated web site, recruitment will be carried out for 5 years so as to register 500 000 volunteers aged ≥ 18 years among whom 60% are expected to be included (having complete baseline data) and followed-up for at least 5 years for 240 000 participants. Questionnaires administered via internet at baseline and each year thereafter will assess socio-demographic and lifestyle characteristics, anthropometry, health status, physical activity and diet. Surveillance of health events will be implemented via questionnaires on hospitalisation and use of medication, and linkage with a national database on vital statistics. Biochemical samples and clinical examination will be collected in a subsample of volunteers.</p> <p>Discussion</p> <p>Self-administered data collection using internet as a complement to collection of biological data will enable identifying nutrition-related risks and protective factors, thereby more clearly elucidating determinants of nutritional status and their interactions. These are necessary steps for further refining nutritional recommendations aimed at improving the health status of populations.</p

Social disparities in food preparation behaviours: a DEDIPAC study

BACKGROUND: The specific role of major socio-economic indicators in influencing food preparation behaviours could reveal distinct socio-economic patterns, thus enabling mechanisms to be understood that contribute to social inequalities in health. This study investigated whether there was an independent association of each socio-economic indicator (education, occupation, income) with food preparation behaviours. METHODS: A total of 62,373 adults participating in the web-based NutriNet-Santé cohort study were included in our cross-sectional analyses. Cooking skills, preparation from scratch and kitchen equipment were assessed using a 0-10-point score; frequency of meal preparation, enjoyment of cooking and willingness to cook better/more frequently were categorical variables. Independent associations between socio-economic factors (education, income and occupation) and food preparation behaviours were assessed using analysis of covariance and logistic regression models stratified by sex. The models simultaneously included the three socio-economic indicators, adjusting for age, household composition and whether or not they were the main cook in the household. RESULTS: Participants with the lowest education, the lowest income group and female manual and office workers spent more time preparing food daily than participants with the highest education, those with the highest income and managerial staff (P < 0.0001). The lowest educated individuals were more likely to be non-cooks than those with the highest education level (Women: OR = 3.36 (1.69;6.69); Men: OR = 1.83 (1.07;3.16)) while female manual and office workers and the never-employed were less likely to be non-cooks (OR = 0.52 (0.28;0.97); OR = 0.30 (0.11;0.77)). Female manual and office workers had lower scores of preparation from scratch and were less likely to want to cook more frequently than managerial staff (P < 0.001 and P < 0.001). Women belonging to the lowest income group had a lower score of kitchen equipment (P < 0.0001) and were less likely to enjoy cooking meal daily (OR = 0.68 (0.45;0.86)) than those with the highest income. CONCLUSION: Lowest socio-economic groups, particularly women, spend more time preparing food than high socioeconomic groups. However, female manual and office workers used less raw or fresh ingredients to prepare meals than managerial staff. In the unfavourable context in France with reduced time spent preparing meals over last decades, our findings showed socioeconomic disparities in food preparation behaviours in women, whereas few differences were observed in men

Lactose Crystallization and Hygroscopicity

During the manufacture of spray-dried milk products, the lactose may crystallize (process during which α-lactose picks up a molecule of water) whereas the hygroscopicity and caking properties decrease. A new modified method was used to determine of the hygroscopicity of whey and milk powders according to the conditions of lactose crystallization. Hygroscopicity was determined using a desiccator with a saturated solution of NaI (39% relative humidity) in the place of NH4Cl (80% relative humidity) at 20°C, in relation to time. Moreover, this new method was performed in static state and not in dynamic conditions (as in reality). Results concerning hygroscopicity are also presented for various milk, whey and lactose powders, with degrees of crystallinity of α-lactose monohydrate ranging from 0 to 100%

The analysis of a set of questionnaires composed of 151 items on salt-, sweet- and fat-liking using LISREL-type and PLS-PM techniques leads to equivalent results

International audienceMeasure of salt-, sweet- and fat-liking is commonly assessed using sensory testing. However, this might become cumbersome with large number of subjects and products to assess. Thus, a questionnaire has been developed and administered through internet (Nutrinet-Sante Study) to a large sample (n=43 807) from the French population. The present study aimed to estimate the structural models underlying each sensory sensation (sweet, salty, fatty and sweet, fatty and salty) and to compute an overall score for each subject over each sensation using structural equation modeling (SEM). Subjects completed 151 questions based on (1) liking towards foods containing high amounts of sugar, or ‘sugar and fat’, or ‘salt and fat’ (9-point scale); (2) favorite level of seasoning with sugar, salt or fat on various foods (6-point scale); (3) favorite dishes (maximum 4) in a restaurant menu; (4) salt-, sweet- and fat-related behavior. The latent variables underlying each sensory sensation were determined using an exploratory factor analysis (principal component solution, varimax rotation; SAS® procedure FACTOR). Second-order models based on these latent variables were subjected to SEM using LISREL-type techniques (SAS® procedure CALIS) and Partial Least Squares-Path Model (PLS-PM, XLStat). Incidentally, PLS-PM (XLStat) consumed much more time than PROC CALIS (SAS®) for second-order models. Nonetheless, both regression coefficient and individual score vectors were highly correlated between the two types of SEM with Pearson’s coefficients greater than 0.75 and 0.95, respectively. In the present study, both types of SEM gave the same interpretation in terms of individual scoring

Thermohygrometric sensor: a tool for optimizing the spray drying process

The introduction of a thermohygrometer into the outlet air of a spray-drying chamber allows measurement and observation of absolute and relative humidities. As an example, there is no powder stuck in a spray-drying chamber of a three-stage pilot plant when the difference between calculated and measured absolute humidity of the outlet air is below 2 g of water kg(-1) dry air. To obtain a whole milk, skim milk or whey powder at 0.20 +/- 0.02 of water activity (at 25 degrees C), the relative humidity of the outlet air must be equal to 11%+/- 1 for whole milk powder and 7%+/- 1 for whey and skim milk powders. (c) 2004 Elsevier Ltd. All rights reserved

Keeping the quality of spray dried dairy ingredients: dependence on water activity and glass transition

The most widely used process for dehydration of dairy products is spray drying. This is an effective method for preserving biological products as it does not involve severe heat treatment and allows storage of powders at ambient temperature. Various authors have reported the physicochemical properties of free and bound water and the effects of water on physical state, transition temperatures, sticking temperature, reaction kinetics and stability of milk products. The emphasis is on the physical state of non-fatty solids and the effects of water and its physical state on chemical reaction rates, growth of micro-organisms and stability. Spray-drying, storage and quality of dairy powders are significantly dependent on both the physical state of lactose (one of the main components of dairy powders) and other carbohydrates, which themselves are dependent on the glass transition temperature (Tg) and water activity (aw). The maximum moisture content of a dairy powder (4% for skim milk powder) is defined in the product specification in relation to aw, and this must be close to 0.2 at 25 ◦C for optimal preservation. In these conditions of water content and aw, the Tg will be close to 50 ◦C. This paper is a short review of the different physical properties required to maintain the quality of dairy ingredient powders

Relative humidity of outlet air: the key parameter to optimize moisture content and water activity of dairy powders

The most widely used technique for dehydration of dairy products is spray drying. This is an effective method for preserving biological products as it does not involve severe heat treatment and allows storage of powders at an ambient temperature. The maximum moisture content of a dairy powder (max 4% for skim milk powder) is defined in the product specification in relation to the water activity, and this must be close to 0.2 at 25 ◦C for optimum preservation. From an economic point of view, it is very important to operate as closely as possible to this limit. Many dairy manufacturers and researchers have demonstrated and reported that powder moisture is related to the outlet air temperature, but this is not always true. The aims of this study were to evaluate the direct and indirect relationships between outlet air temperature and moisture content of skim milk powder in relation to the spray-drying parameters (concentrate mass flow rate, absolute humidity of inlet air and inlet air temperature) using a thermodynamic approach. Our experiments showed that moisture content of skim milk powder can be close to 5.1 ± 0.0% with variations in outlet air temperature of 77 to 87 ◦C. Other experiments showed that the powder moisture content can vary from 4.6 ± 0.0% to 5.2 ± 0.0% even when the outlet air temperature remains close to 86 ± 1 ◦C. These results indicate that there is no direct relationship between outlet air temperature and powder moisture content. It is preferable to use the Enthalpic Mollier-Ramzine diagram of wet air and certain transfer equations related to the Fick and Fourier laws to demonstrate that the powder moisture content is directly related to the relative humidity (RH) of the outlet air. The moisture content and water activity of skim milk powder were close to 5.1 ± 0.0% and 0.27 ± 0.01 for outlet air RH close to 7.0 ± 0.1%, respectively, whatever the other drying parameter values. We demonstrated in this study that control of the RH of the outlet air is at least as important as control of the outlet air temperature to optimize the moisture content of a dairy powder, regardless of the absolute humidity of the inlet air, concentrate mass flow rate or inlet air temperature

Technologie des poudres laitières

Technologie des poudres laitières. Journée Bretagne Technologie Alimentair