Comparison of crystallized coconut sugar produced by traditional method and amorphous coconut sugar formed by two drying methods: vacuum drying and spray drying

Coconut sugar is traditionally produced by evaporating sap until reaching its saturated liquid and formed a crystalline structure. This study investigated the comparison of coconut sugar made by traditional method (crystalline structure) and dried coconut sugar (predominantly amorphous structure) to its characteristics. Two different formulation of coconut sap : maltodextrin (7 : 3) and (6 : 4) (weight/weight) were dried using vacuum oven (70℃, 6 hours) and spray dried (Tinlet 120℃.) Coconut sugar was characterized for moisture content, crystallinity, water sorption isotherm, hygroscopic rate, color, dissolving time, and powder recovery. Initial moisture content was examined and in range of 1.33% - 3.44% (wb). The highest monolayer water content was obtained by using spray drying (6 : 4) and lowest was obtained by traditional method. X-ray diffraction showed that dried coconut sugar powder had dominant amorphous structure (70.9 – 71.4%) while traditional one was dominated with crystalline structure (90.5%). Traditional coconut sugar was the least hygroscopic (1.21 × 10-4 g water/g solid/minutes), followed by vacuum dried coconut sugar (1.48 × 10-4 g water/g solid/minutes) and spray dried ones (1.56 – 1.67 × 10-4 g water/g solid/minutes). Spray dried coconut sugar had the brightest and the whitest color, followed by vacuum dried and traditional coconut sugar. Vacuum dried powder was quicker to dissolve (13.33 – 16.67 s), while increasing maltodextrin in spray drying could not decrease the dissolving time. The highest powder recovery of dried sugar was obtained by using vacuum drying and higher maltodextrin concentration (88.70%) while traditional method produced 100% powder recovery.     

Application of a novel de-watering process to control kiln brown stain in radiata pine

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Pinus radiata mehreren Trocknungszyklen mit Pressluft zwischen 10 und 100 bar unterworfen. Danach wurde die Abnahme der Feuchte, der Feuchtegradient entlang der Proben und das Ausma? der Verf?rbung durch Braunverf?rbung bestimmt. Die Ergebnisse zeigen, da? die Anwendung der Druckzyklen bis 100 bar zu einer gleichf?rmigen Feuchteverteilung führt mit Mittelwerten um 40%. Die Braunverf?rbung war vollst?ndig verhindert. Demgegenüber zeigten alle Proben, die mit niedrigen Drücken behandelt waren, starke Verf?rbungen, denn der Feuchtegehalt blieb zu hoch, um einen Massenflu? zu verhindern. Dies zeigt, da? ein Massenflu? von Vorstufen der Braunverf?rbungen wesentlich ist für die Entwicklung der Verf?rbungen w?hrend des Trocknens von Kiefern-Splintholz. M?glichkeiten für praktische Anwendungen dieser Untersuchungen werden diskutiert.

     

The supervisory pc in process control systems with special reference to the kiln drying of wood

The personal computer (PC) has invaded the process control industry. Because of the wide ranging advantages it provides at relatively low cost. The PC can be an effective management tool when used as a supervisor in a control system. It is then usually connected into a network system together with many other intelligent process controllers. The supervisory PC will provide a plant-wide real-time status report of important critical operational parameters which can be used for managerial decisions. Such a distributed control system can, for example, be employed very advantageously by a saw-mill operating a battery of wood drying kilns.     

Optimization of operating process parameters for instant brown rice production with microwave-followed by convective hot air drying

Nowadays, instant or quick cooking brown rice is a food product that has marketing potential due to the life style of new generation. This research mainly aimed to characterize, model and optimize the key processing conditions including water-rice ratio (WRR), microwave power level (MWL) and hot air temperature (HAT) for producing instant brown rice by applying Box-Behnken technique. The process responses comprised with color, rehydration ratio and textural qualities of products. The microscopic images of products were also determined. The result indicated that MWL caused the most intense effect on the rehydration ratio and textural qualities. Furthermore, the MWL and HAT influenced on the lightness while the WRR affected on the hardness of rehydrated samples. All three processing parameters significantly affected on the color intensity and stickiness of rehydrated rice. The optimal processing conditions for WRR, MWL and HAT were 1.44, 499.8 W and 89.99 °C respectively with 88% overall desirability.     

Manufacture of jameed using a spray drying process: a preliminary study

Jameed powder was manufactured using a controlled fermentation with a yogurt starter followed by spray drying. The composition and physical properties of the spray dried jameed were analysed and compared with local sun dried jameed. It was found that the moisture content of the spray dried jameed was lower than that of the sun dried product. In addition, the dispersibility of the spray dried jameed was higher and the average particle size was smaller; wettability, bulk density and colour were comparable between the two products.     

直投式发酵剂制备的哈尔滨风干肠在成熟过程中的理化及微生物特性变化

采用三种由自然发酵分离鉴定出的微生物,按一定比例混合制备复合发酵剂,将其用于哈尔滨风干肠中,研究其对风干肠的理化性质、微生物变化和游离氨基酸含量的影响。实验分为三组,分别为对照组,添加普通发酵剂组和添加直投式发酵剂组。结果表明:添加发酵剂的风干肠pH明显低于对照组,且添加直投式发酵剂的pH最低(P<0.05);添加发酵剂会使产品的游离氨基酸含量显著提高(P<0.05)、感官品质也较好(P<0.05),而各组水分活度变化差异不明显,这说明直投式发酵剂具有很好的活力和发酵性能,能够显著提高风干肠的质量,缩短发酵时间。     

Moisture migration by magnetic resonance imaging during eggplant drying: a preliminary study

The paper investigated the effect of hot‐air drying (50, 60 °C) on the physical properties of cylindrical eggplant samples. Drying kinetics, water profiles along longitudinal and transversal sample sections through nuclear magnetic resonance imaging (MRI) and volumetric shrinkage were determined. During the drying process at 50 °C, the volume of removed water was found lower than the reduction in sample volume, while at 60 °C it was higher. MRI showed that the water migration mainly occurs transversally than longitudinally. The curves of mass water loss obtained by both the standard weighting method and MRI showed conformity. Experimental data of moisture ratio and of shrinkage volume were fitted using empirical models available in the literature. This preliminary study showed that the nondestructive MRI technique offers the possibility to study water distribution in food during drying processes. The quantitative moisture distribution maps allow future development and verification of models for prediction of mass transport phenomena in foods during drying.     

A comparative study of beef quality after ageing longissimus muscle using a dry ageing bag,traditional dry ageing or vacuum package ageing

The objective of this study was to investigate beef quality of longissimus muscle after ageing in dry ageing bags, traditional dry ageing or vacuum for 8 or 19 days. Lower ageing weight loss, odour score and microbial growth were found in meat aged in dry ageing bags than after traditional dry ageing. The sensory panel detected no differences for most of the sensory attributes between samples using the two dry ageing methods, except for the odour of the cutting surface. The dry-aged steaks had more umami and butter fried meat taste compared with vacuum-aged steaks. Ageing time affected most of the sensory traits in this study, which improved as ageing time increased from 8 to 19 days. In a consumer test, meat aged for 21 days in dry ageing bags was preferred than the samples aged in vacuum. This may be due to the higher tenderness and juiciness obtained during storage in dry ageing bags than meat aged in vacuum.     

Effects of process parameters on quality changes of shrimp during drying in a jet-spouted bed dryer

ABSTRACT:  The objective of the present study was to investigate the effects of various parameters, that is, concentration of salt solution (2%, 3%, 4%[w/v]), boiling time (3, 5, 7 min), drying air temperature (80, 100, 120 °C), and size of shrimp, on the kinetics of drying and various quality attributes of shrimp, namely, shrinkage, rehydration ability, texture, colors, and microstructure, during drying in a jet-spouted bed dryer. In addition, the effects of these processing parameters on the sensory attributes of dried shrimp were also investigated. Small shrimp (350 to 360 shrimp/kg) and large shrimp (150 to 160 shrimp/kg) were boiled and then dried until their moisture content was around 25% (d.b.). It was found that the degree of color changes, toughness, and shrinkage of shrimp increased while the rehydration ability decreased with an increase in the concentration of salt solution and boiling time. Size of shrimp and drying temperature significantly affected all quality attributes of dried shrimp. The conditions that gave the highest hedonic scores of sensory evaluation for small dried shrimp are the concentration of salt solution of 2% (w/v), boiling time of 7 min, and drying air temperature of 120 °C. On the other hand, the conditions that gave the highest hedonic scores of sensory evaluation for large dried shrimp are the concentration of salt solution of 4% (w/v), boiling time of 7 min, and drying air temperature of 100 °C. The quality attributes of dried shrimp measured by instruments correlated well with the sensory attributes, especially the color of dried shrimp.     

欧姆加热对豆浆风味物质的影响

为研究蛋白酶影响豆浆风味的作用机理,在豆浆机制备豆浆中分别添加不同浓度的木瓜蛋白酶（15000、30000、45000、60000、75000 U/L）、氨基肽酶（500、1000、1500、2000、2500 U/L）、风味蛋白酶（100、150、200、250、300 U/L）和碱性蛋白酶（500、1500、2500、3500、4500 U/L）进行酶解,以不加酶的豆浆机制备豆浆为空白对照组、传统方法制备的豆浆为生豆对照组,对热生香后的豆浆进行感官评价,测定酶解、热生香后豆浆中的多肽和氨基酸态氮含量及变化量,并分析其与感官风味指标的相关性。采用顶空固相微萃取结合气相色谱-质谱联用技术,分析了豆浆中的挥发性风味物质。结果表明,空白对照组热生香后豆浆的豆腥味、豆香味比生豆对照组更淡,而多肽和氨基酸含量分别比生豆对照组降低了37.98%和25.78%。实验组添加250 U/L风味蛋白酶的豆浆感官评分最高,与空白对照组相比提高了118.41%。除添加4500 U/L碱性蛋白酶处理组外,添加蛋白酶后豆浆的感官评分均显著高于空白对照组（P<0.05）。加酶样品中与豆腥味相关的正己醛、2-戊基呋喃、正己醇、反,反-2,4-癸二烯醛等挥发性化合物含量均低于空白对照组和生豆对照组,与豆香气相关的挥发性化合物含量和种类均有不同程度提升。添加外源蛋白酶处理能明显提高豆浆中多肽和氨基酸含量,其中添加4500 U/L碱性蛋白酶时多肽含量最高（2.30±0.15 g/L）,添加2500 U/L氨基肽酶时氨基酸含量最高（0.087±0.0045 g/L）。风味蛋白酶处理组中酶解豆浆氨基酸态氮含量与豆香味得分呈显著正相关（P<0.05）,其他三种酶的多肽增加量均与豆腥味得分呈显著或极显著正相关（P<0.05,P<0.01）,氨基肽酶处理组中,氨基酸态氮增加量与豆腥味、豆香味和总分呈显著负相关（P<0.05）。以上结果表明,添加外源蛋白酶可以增加豆浆中多肽和氨基酸等风味前体物质的含量,制成豆腥味更淡、豆香味更丰富的豆浆。本研究为豆浆制备工艺的优化提供了理论指导。     

Determination of Amylose in Flour by a Colorimetric Assay: Collaborative Study

An improved colorimetric method, based on the well-known reaction between amylose and iodine, is described. During a first step, flour is dissolved in dimethylsulfoxide and the starch precipitated with ethanol. The extracted starch is redissolved in urea-dimethylsulfoxide and the resulting solution defatted with ethanol. An aliquot of the lipid-free solution is then reacted with iodine and the absorbance of the blue-coloured amylose-iodine complex measured, thus determining the iodine-binding capacity of starch (Blue Value). A collaborative study was conducted, according to official guidelines, to determine the method's repeatability and reproducibility: 9 participants were each sent 7 flour samples from different botanic origin for duplicate analysis. Statistical evaluation of the results showed satisfactory precision, with an average repeatability relative standard deviation of 2.6% and an average reproducibility relative standard deviation of 9.1%. The proposed method can, therefore, be considered as reliable and can be used for routine analysis.     

Systemic concentrations of hormones during the development of follicular waves in mares and women: a comparative study

Changes in systemic concentrations of FSH, LH, oestradiol and progesterone during the ovulatory follicular wave were compared between 30 mares and 30 women. Based on a previous study, the emergence of the future ovulatory follicle was defined as occurring at 13.0 mm in mares and 6.0 mm in women, and deviation in diameter between the two largest follicles was expected to begin at 22.7 mm in mares and 10.3 mm in women. Mean FSH concentrations were high in mares during the luteal phase, resulting from statistically identified FSH surges occurring in individuals on different days and in different numbers (mean, 1.5 +/- 0.2 surges/mare); the internadir interval was 3.9 +/- 0.3 days. In contrast, mean FSH in women was low during the luteal phase and increased to a prolonged elevation during the follicular phase. The prolonged elevation was apparent in each individual (internadir interval, 15.2 +/- 0.4 days). Changes in LH or oestradiol concentrations encompassing deviation were not detected in mares, but both hormones increased slightly but significantly between emergence and deviation in women. The hypothesis that a greater number of growing follicles causes a greater predeviation decrease in FSH was supported for mares (r, -0.39; P< 0.04), but a similar negative correlation (r, -0.36) was not significant in women. The hypothesis that the increase in oestradiol during the luteal phase in women was at least partly attributable to luteal-phase anovulatory follicular waves was not supported. Normalization of FSH concentrations to the day of emergence showed maximum value on the day of emergence with a significant increase and decrease on each side of emergence in both species. The day of expected deviation occurred 3 days after emergence during the decline in FSH in both species. These results indicated that the previously reported striking similarities in emergence and deviation between mares and women during the ovulatory follicular wave are associated with species similarities in the temporal relationships between follicle events and FSH concentration changes. Thus, mares may be useful research models for studying the role and mechanism of the action of FSH in emergence and deviation during the ovulatory follicular wave in women.     

Identification and safety evaluation of Bacillus species occurring in high numbers during spontaneous fermentations to produce Gergoush, a traditional Sudanese bread snack

Gergoush is a naturally fermented Sudanese Bread snack produced in three fermentation steps (primary starter, adapted starter and final dough), followed by three baking steps for a half to one hour at above 200 °C. This study examines the microbiota of two sets of fermentations performed at a traditional production site in Khartoum, Sudan in 2006 and 2009, respectively. In 2006 four different milk/legume based primary starters (faba bean, chick pea, lentil and white bean) were sampled in order to enumerate and identify the Bacillus at species or group level. In 2009 specific focus was on the enumeration and safety evaluation of the dominant Bacillus cereus group species occurring during various Gergoush productions (including the three fermentations steps and after baking). In 2006, the primary starters contained Bacillus spp. in the order of between 7.7 and 8.1 log₁₀ CFU/g. Species identifications were performed by M13-PCR typing using the Escherichia coli phage M13 derived primer PM13 combined with internally transcribed 16-23S rRNA PCR, 16S rRNA gene and gyrA or gyrB gene sequencing, and selected phenotypic tests. Depending on the legume used, 40-68% of the isolates were identified as B. cereus sensu lato, 16-27% as Bacillus licheniformis, 8-32% as Bacillus subtilis and 4-20% as Bacillus sonorensis. During the second set of fermentation trials performed in 2009, the Bacillus spp. and B. cereus occurred in numbers of between 7.7-9.9 and 6.1-7.8 log₁₀ CFU/g, respectively, while no bacteria were detected after baking. A total of 180 B. cereus sensu lato isolates from four different primary starters, adapted starters and final doughs were further identified as B. cereus sensu stricto (118 isolates) and Bacillus thuringiensis (62 isolates). The safety of Gergoush was evaluated based on the counts and toxin gene profiles of the dominant B. cereus species. Considering that no bacteria survived the baking process, and that the cereulide synthetase gene cesB involved in the production of the heat stable emetic toxin cereulide was not detected in any of the investigated B. cereus isolates, the results indicate, that Gergoush produced at the traditional production site is safe for human consumption. This study is the first to identify the Bacillus of Gergoush to species level, and it is the first to perform a safety evaluation of the product, based on the dominant B. cereus species.