The particle size distribution in colombian rice polishings and its effect on gas production by rumen micro-organisms in vitro

Author(s):  
D. Cardenas Garcia ◽  
H. Galbraith ◽  
C.J. Newbold ◽  
J.A. Rooke

Rice polishings (RP) which are produced as a by-product during the pearling of hulled rice have been successfully used as a supplementary food for ruminants. However, information on the effects of feeding RP on rumen fermentation is contradictory. Valdez et al. (1977) found RP had little effect on rumen fermentation in bulls and suggested that the stimulation in growth rate observed, with RP may be mediated by the provision of nutrients postruminally. In contrast, Cardenas et al. (1992) reported that RP stimulated volatile fatty acid concentrations and microbial numbers when added to a rumen simulating fermentor (Rusitec). One reason for these differences might be that changes in the milling process, used to produce RP, have resulted in a by-product with different physical characteristics to that used in earlier studies. The experiment described here was designed to investigate the particle size distribution in Colombian rice polishings and the effect of these fractions on the rumen fermentation in vitro.

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2105 ◽  
Author(s):  
Aleixandre ◽  
Benavent-Gil ◽  
Rosell

The growing interest in controlling the glycemic index of starchy-rich food has encouraged research about the role of the physical structure of food. The aim of this research was to understand the impact of the structure and the in vitro oral processing methods on bolus behavior and starch hydrolysis of wheat bread. Two different bread structures (loaf bread and bread roll) were obtained using different shaping methods. Starch hydrolysis during in vitro oro-gastro-intestinal digestion using the INFOGEST protocol was analyzed and oral processing was simulated by applying two different disintegration processes (basic homogenizer, crystal balls). The bread structure, and thus the shaping method during breadmaking, significantly affected the bolus particle size during all digestion stages. The different in vitro oral processing methods affected the bolus particle sizes after the oral phase in both breads, but they affected the particle size distribution after the gastric and intestinal phase only in the case of loaf bread. Aggregates were observed in the gastric phase, which were significantly reduced in the intestinal phase. When simulated oral processing with crystal balls led to bigger particle size distribution, bread rolls presented the highest in vitro starch hydrolysis. The type of in vitro oral processing allowed discrimination of the performance of the structures of the two breads during starch hydrolysis. Overall, crumb structure significantly affected texture properties, but also had a significant impact on particle size during digestion and starch digestibility.


2005 ◽  
Vol 81 (1) ◽  
pp. 31-38 ◽  
Author(s):  
M. L. Tejido ◽  
M. J. Ranilla ◽  
R. García-Martínez ◽  
M. D. Carro

AbstractThe effects of two concentrations of disodium malate on thein vitrofermentation of three substrates differing in their forage: concentrate ratio (0·8: 0·2, 0·5: 0·5 and 0·2: 0·8; g/g dry matter; low-, medium- and high-concentrate substrates, respectively) by rumen micro-organisms were studied using batch cultures. Rumen contents were collected from four Merino sheep offered lucerne hay ad libitum and supplemented daily with 400 g concentrate. Disodium malate was added to the incubation bottles to achieve final concentrations of 0, 4 and 8 mmol/l malate and15N was used as a microbial marker. Gas production was measured at regular intervals from 0 to 120 h of incubation to study fermentation kinetics. When gas production values were corrected for gas released from added malate, no effects (P> 0·05) of malate were detected for any of the estimated gas production parameters. In 17-h incubations, the final pH and total volatile fatty acid (VFA) production were increased (P< 0·001) by the addition of malate, but no changes (P> 0·05) were detected in the final amounts of ammonia-N and lactate. When net VFA productions were corrected for the amount of VFA produced from malate fermentation itself, adding malate did not affect (P> 0·05) the production of acetate, propionate and total VFA. Malate reduced methane (CH4) production by proportionately 0·058, 0·013 and 0·054 for the low-, medium- and high-concentrate substrates, respectively. Adding malate to batch cultures increased (P< 0·01) rumen microbial growth (mean values of 16·6, 18·3 and 18·4 mg of microbial N for malate at 0, 4 and 8 mmol/l, respectively), but did not affect (P> 0·05) its efficiency of growth (55·5, 56·7 and 54·3 mg of microbial N per g of organic matter apparently fermented for malate at 0, 4 and 8 mmol/l, respectively). There were no interactions (P> 0·05) malate × substrate for any of the measured variables, and no differences (P> 0·05) in pH, CH4production and microbial growth were found between malate at 4 and 8 mmol/l. The results indicate that malate had a beneficial effect on in vitro rumen fermentation of substrates by increasing VFA production and microbial growth, and that only subtle differences in the effects of malate were observed between substrates. Most of the observed effects, however, seem to be due to fermentation of malate itself.


2021 ◽  
pp. 4-4
Author(s):  
Nemanja Bojanic ◽  
Aleksandar Fistes ◽  
Tatjana Dosenovic ◽  
Aleksandar Takaci ◽  
Mirjana Brdar ◽  
...  

A method based on the reverse breakage matrix approach is proposed for controlling the effects that milling has on the particle size distribution and composition of the comminuted material. Applicability, possibilities, and limitations of the proposed method are tested on examples related to the process of wheat flour milling. It has been shown that the reverse matrix approach can be successfully used for defining the particle size distribution of the input material leading to the desired, predetermined particle size and compositional distribution in the output material. Moreover, we have illustrated that it is possible to simultaneously control both, input and output particle size distribution, together with the composition of the output material.


Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 862
Author(s):  
José Delgado ◽  
Freddy A. Lucay ◽  
Felipe D. Sepúlveda

Uncertainty in industrial processes is very common, but it is particularly high in the grinding process (GP), due to the set of interacting operating/design parameters. This uncertainty can be evaluated in different ways, but, without a doubt, one of the most important parameters that characterise all GPs is the particle size distribution (PSD). However, is the PSD a good way to quantify the uncertainty in the milling process? This is the question we attempt to answer in this paper. To do so, we use 10 experimental grinding repetitions, 3 grinding times, and 14 Tyler meshes (more than 400 experimental results). The most relevant results were compared for the weight percentage for each size (WPES), cumulative weight undersize (CWU), or the use of particle size distribution models (PSDM), in terms of continuous changes in statistical parameters in WPES for different grinding times. The probability distribution was found to be changeable when reporting the results of WPES/CWU/PSDM, we detected the over-/under-estimation of uncertainty when using WPES/CWU, and variations in the relationships between sizes were observed when using WPES/CWU. Finally, our conclusion was that the way in which the data are analysed is not trivial, due to the possible deviations that may occur in the uncertainty process.


Author(s):  
Amol A. Tatode ◽  
Arun T. Patil ◽  
Milind J. Umekar ◽  
Darshan R. Telange

Objective: Aim of the present investigation was to determine the effect of various synthetic grades of phospholipids on paclitaxel liposomes (PTL).Methods: The PTL formulations using various grades of phospholipids were prepared by film hydration method. The prepared PTL formulations were physicochemically characterized by entrapment efficiency (EE, %w/w), vesicular size and particle size distribution. These formulations were also characterized for function parameters such as in vitro release and hemolytic toxicity assay.Results: The synthetic grades of phospholipids significantly influenced PTL formulations. The stoichiometric ratio (1:1) between CH and various synthetic phospholipids was found to be optimized one, from rest of the ratios. The characterization confirmed the formation of PTL. The EE was observed to be high (86.67%) as increasing the ratios between CH and phospholipids but then declined suddenly as further increasing the ratio. The best liposomal formulations showed that the spherical shape was found to be within size ranging from<10 µm, with a higher rate and extent of the release, ~86.22% of paclitaxel from PTL formulation. The results of the hemolytic toxicity study demonstrated that PTL formulations with a ratio (1:1) exhibited a significantly lower hemolytic toxicity (2.70%), compared to all formulations.Conclusion: The result revealed the excellent effect of phospholipids on paclitaxel liposomes. The paclitaxel liposomes prepared with CH: PL90G ratio (1:1) was found to be optimized one. The entrapment efficiency, particle size distribution, in vitro release and hemolytic activity with this ratio shown to be excellent as compared to other ratios.


Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1571 ◽  
Author(s):  
Fanchao Meng ◽  
Yating Sun ◽  
Robert J. Lee ◽  
Guiyuan Wang ◽  
Xiaolong Zheng ◽  
...  

Microfluidic technology (MF) has improved the formulation of nanoparticles (NPs) by achieving uniform particle size distribution, controllable particle size, and consistency. Moreover, because liquid mixing can be precisely controlled in the pores of the microfluidic chip, maintaining high mixing efficiency, MF exerts higher of NP encapsulation efficiency (EE) than conventional methods. MF-NPs-cabazitaxel (CTX) particles (MF-NPs-CTX) were first prepared by encapsulating CTX according to MF. Folate (FA)- Polyethylene glycol (PEG)-NPs-CTX particles (FA-PEG-NPs-CTX) were formulated by connecting FA to MF-NPs-CTX to endow NPs with targeted delivery capability. Accordingly, the mean particle size of FA-PEG-NPs-CTX increased by approximately 25 nm, as compared with MF-NPs-CTX. Upon morphological observation of FA-PEG-NPs-CTX and MF-NPs-CTX by transmission electron microscopy (TEM), all NPs were spherical and particle size distribution was uniform. Moreover, the increased delivery efficiency of CTX in vitro and its strong tumor inhibition in vivo indicated that FA-PEG-NPs-CTX had a powerful tumor-suppressive effect both in vitro and in vivo. In vivo imaging and pharmacokinetic data confirmed that FA-PEG-NPs-CTX had good drug delivery efficiency. Taken together, FA-PEG-NPs-CTX particles prepared using MF showed high efficient and targeted drug delivery and may have a considerable driving effect on the clinical application of targeting albumin NPs.


2009 ◽  
Vol 103 (8) ◽  
pp. 1167-1173 ◽  
Author(s):  
Tjalling W. de Vries ◽  
Bart L. Rottier ◽  
Doetie Gjaltema ◽  
Paul Hagedoorn ◽  
Henderik W. Frijlink ◽  
...  

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