Storage of milk powders under adverse conditions: 2. Influence on the content of water-soluble vitamins

1. Storage of milk powder under unfavourable conditions accelerates the normally slow deterioration in nutritional quality. The effects of such storage on the water-soluble vitamin composition were examined. 2. (a) Spray-dried whole milk containing 25 g water/kg was stored at 60° and 70° and sampled weekly to 9 weeks. (b) Spray-dried whole milk and skimmed milk were adjusted to contain 40 and 100 g water/kg and stored at 37° in nitrogenand in oxygen. Samples were taken for analysis at intervals during storage. 3. The samples were analysed for eight B-complex vitamins and ascorbic acid, and also for total lysine, ‘reactive lysine' and ‘lysine as lactulosyl-lysine'. 4. Storage at 60° caused rapid destruction of folic acid (53% loss at 4 weeks) and slower loss of thiamin, vitamin B6 and pantothenic acid (18% at 8 weeks). There was no change in the content of riboflavin, biotin, nicotinic acid and vitamin B12. At 70° the rate of destruction of the four labile vitamins was much increased; 18% or less survived at 4 weeks. 5. At 37° and 40 g water/kg there was little change in total and ‘reactive' lysine during storage for 57 d. Lactulosyl-lysine was demonstrably present butatlow concentration. There was considerable loss of folate (72%) and ascorbate (91%) during storage for 30 d in O2, but no significant loss in N2. Thiamin fell by approximately 12% in 57 d, equally in O2 and N2. The content of the remaining vitamins was unchanged. At 100 g water/kg there were progressive Maillard changes. During 27 d in N2 the colour changed from cream to palebrown, but in O2 there was no perceptible colour change. Total lysine fell by 20% in 27 d, and ‘reactive lysine' by 30%. Folate was stable during 16 d in N2, but largely (94%) destroyed in O2. Ascorbic acid was also destroyed in N2 as in O2. Thiamin fell by 41% in 27 d, equally in O2 and N2. Vitamin B6 was more labile, especially in N2, falling by 71% in 16d. 6. With skimmed-milk powder containing 100 g water/kg, storage at 37° in O2 and N2 gave much the same results as for the corresponding whole-milk powder. The presence of milk fat had no marked effect on the stability of the water-soluble vitamins. 7. Destruction of vitamins was clearly linked to the progress of Maillard-type reactions and was strongly influenced by time and temperature of storage, moisture content and, in some instances, by the presence of O

Storage of milk powders under adverse conditions: 1. Losses of lysine and of other essential amino acids as determined by chemical and microbiological methods

1. Whole-milk powders containing 25 g water/kg were stored for up to 9 weeks in sealed aluminium containers at elevated temperatures. Lysine and other essential amino acids were measured by chemical and microbiological methods. 2. Storage at 60° resulted in the progressive formation of lactulosyl-lysine. After 9 weeks, 30% of the lysine groups were present in this form. The powders still retained their natural colour and the levels of tryptophan, methionine, cyst(e)ine and leucine remained unchanged. 3. Storage at 70° resulted in the formation of lactulosyl-lysine followed by its complete degradation with the development of browning. Available tryptophan, methione, leucine and isoleucine decreased progressively during storage. 4. The different methods for lysine determination gave widely dissimilar results. The direct fluorodinitrobenzene (FDNB) technique and reactive lysine from furosine were considered to be the most reliable methods. The FDNB-difference, dye-binding lysine, Tetrahymena and Pediococcus methods all seriously underestimated reactive or available lysine in heat-damaged milk powders. Tetrahymena and Pediococcus appeared to utilize lactulosyl-lysine as a source of lysine. 5. The results are discussed in relation to storage and distribution of milk powders in hot climate

The effect of Maillard reaction products on zinc metabolism in the rat

The effect of giving Maillard reaction products (MRP) on zinc metabolism was investigated in the rat. In Expt 1, MRP were prepared by incubating casein with either glucose or lactose under controlled reaction conditions, and were quantified as either ‘early' or ‘advanced' after estimation of lysine loss and lysine destruction respectively. In Expt 2, the effect of the purified early MRP fructose-lysine (FL) on Zn metabolism was studied. The experimental diets containing 20 mg Zn/kg were given to weanling rats for 21 d. Zn balance was assessed over 9-14 d (Expt 1), or 1-14 d (Expt 2). Femur, liver, kidney and serum Zn concentrations were determined at 21 d. The major effect of the MRP in the casein-sugar mixtures was on urinary Zn excretion. The casein-glucose MRP induced up to a 6-fold increase in the quantity of Zn excreted in the urine. The magnitude of the hyperzincuria increased with the extent of the Maillard reaction. Similar dietary levels of casein-lactose MRP increased urinary Zn loss 2-fold. Free FL had no effect on urinary Zn. Faecal Zn, Zn retention, liver, femur and serum Zn were generally not influenced by giving MRP from casein-sugar mixtures or by giving free FL, although kidney Zn was decreased in rats fed on FL. It was concluded that although urinary Zn excretion can be increased by the presence of MRP in the diet, this is only a minor excretory pathway and would have little influence on overall Zn nutrition in individuals fed on a diet adequate in Z

Contact Force Dependence on Relative Humidity: Investigations Using Atomic Force Microscopy

This paper deals with the ability of scanning force microscopy to determine contact forces of various materials. Indeed, with high spring constants at low relative humidity, the nature of the material can be determined by measurement of the contact force as the tip approaches. Cantilevers with a high spring constant are used to achieve solid-solid contact for the tip-sample system. The capillary force estimation provides information on the development of the height of the water meniscus formed between the tip and different surfaces depending on the relative humidity. Finally, we focus our attention on measurements of moduli of elasticity which vary with the physicochemical processes (precipitation, dissolution, water intercalation, dehydration) instigated by the variation in humidity. All experiments were conducted on various surfaces: more extensively on gypsum, but also on calcite, mica, graphite, brucite, aluminum, silver and glass

From nanotechnology to nanomedicine: applications to cancer research

Scientific advances have significantly improved the practice of medicine by providing objective and quantitative means for exploring the human body and disease states. These innovative technologies have already profoundly improved disease detection, imaging, treatment and patient follow-up. Today's analytical limits are at the nanoscale level (one-billionth of a meter) enabling a detailed exploration at the level of DNA, RNA, proteins and metabolites which are in fact nano-objects. This translational review aims at integrating some recent advances from micro- and nano-technologies with high potential for improving daily oncology practice

Bit-Error-Rate Assessment of 170-Gb/s Regeneration Using a Saturable Absorber and a Nonlinear-Fiber-Based Power Limiter

International audienceA 170-Gb/s all-optical 2R regenerator made up of a fast saturable absorber and a highly nonlinear-fiber-based power limiter is reported for the first time. Bit-error-rate assessment of one of the four 42.5-Gb/s optical time-division-multiplexed tributaries shows a receiver sensitivity improvement

Generating and measuring the anisotropic elastic behaviour of Co thin films with oriented surface nano-strings on micro-cantilevers

In this research, the elastic behaviour of two Co thin films simultaneously deposited in an off-normal angle method was studied. Towards this end, two Si micro-cantilevers were simultaneously coated using pulsed laser deposition at an oblique angle, creating a Co nano-string surface morphology with a predetermined orientation. The selected position of each micro-cantilever during the coating process created longitudinal or transverse nano-strings. The anisotropic elastic behaviour of these Co films was determined by measuring the changes that took place in the resonant frequency of each micro-cantilever after this process of creating differently oriented plasma coatings had been completed. This differential procedure allowed us to determine the difference between the Young's modulus of the different films based on the different direction of the nano-strings. This difference was determined to be, at least, the 20% of the Young's modulus of the bulk Co

A card game for the treatment of delusional ideas: A naturalistic pilot trial

BACKGROUND: "Michael's game" is a card game which aims at familiarizing healthcare professionals and patients with cognitive behavioral therapy of psychotic symptoms. This naturalistic study tests the feasibility and the impact of the intervention in various naturalistic settings. METHOD: Fifty five patients were recruited in seven centers. They were assessed in pre and post-test with the Peters Delusion Inventory – 21 items (PDI-21). RESULTS: Forty five patients completed the intervention significantly reducing their conviction and preoccupation scores on the PDI-21. CONCLUSION: This pilot study supports the feasibility and effectiveness of "Michael's game" in naturalistic setting. Additional studies could validate the game in a controlled fashion

On-chip generation of high-dimensional entangled quantum states and their coherent control

Optical quantum states based on entangled photons are essential for solving questions in fundamental physics and are at the heart of quantum information science1. Specifically, the realization of high-dimensional states (D-level quantum systems, that is, qudits, with D > 2) and their control are necessary for fundamental investigations of quantum mechanics2, for increasing the sensitivity of quantum imaging schemes3, for improving the robustness and key rate of quantum communication protocols4, for enabling a richer variety of quantum simulations5, and for achieving more efficient and error-tolerant quantum computation6. Integrated photonics has recently become a leading platform for the compact, cost-efficient, and stable generation and processing of non-classical optical states7. However, so far, integrated entangled quantum sources have been limited to qubits (D = 2)8, 9, 10, 11. Here we demonstrate on-chip generation of entangled qudit states, where the photons are created in a coherent superposition of multiple high-purity frequency modes. In particular, we confirm the realization of a quantum system with at least one hundred dimensions, formed by two entangled qudits with D = 10. Furthermore, using state-of-the-art, yet off-the-shelf telecommunications components, we introduce a coherent manipulation platform with which to control frequency-entangled states, capable of performing deterministic high-dimensional gate operations. We validate this platform by measuring Bell inequality violations and performing quantum state tomography. Our work enables the generation and processing of high-dimensional quantum states in a single spatial mode