蛇纹石细小纤维性质及其对密封纸板性能的影响

通过筛分的方法,收集蛇纹石纤维原料中的细小纤维,分析其基本性质,然后按不同比例将其与长纤维混合,研究细小纤维对密封纸板强度性能、压缩回弹性能的影响。结果表明:经200目筛分所收集到的细小纤维为负电性。在磨浆1500r的长纤维中添加细小纤维,随着添加量的增加,密封纸板的抗张指数先增大后减小,压缩率先降低后升高,而回弹率先升高后降低。在细小纤维添加量为30%时,密封纸板的抗张指数达到11.88N.m/g,压缩率和回弹率分别为39.228%、27.420%,密封纸板具有较好的综合性能。     

Sensory properties of akara (fried cowpea paste) prepared from paste stored at low storage temperatures

Akara (fried cowpea paste) a popular West African cowpea (Visna unguiculata) product was prepared from cowpea paste stored under refrigeration (4‐6°C) and freezer (‐18°C) temperatures for 10 and 24 days respectively. Blanched and unblanched paste were stored. Akara from freshly prepared paste was used as control. The sensory properties investigated were colour, taste, texture and aroma. Akara from various paste samples; refrigerator stored paste (RSP) freezer stored paste (FSP) and fresh paste (FP) were rated for the various attributes and the degree of difference from the control by a trained panel. Sensory attributes of RSP akara were majorly rated between good and fair in the first 3 days. Attributes were rated between fair and bad by the 6^th and 10^th days of storage and were significantly different from FP akara. Sensory attributes of FSP akara were rated between good and fair until the 17^th day of storage. Blanching proved beneficial as a pre‐storage treatment for the preservation of akara texture in the first 3 days for RSP and for 24 days for FSP. The results showed that the properties of cowpea paste which influence texture and overall sensory quality of akara, were better preserved in frozen storage. The implications of the results on the feasibility of bulk production and storage of cowpea paste for retail as a frozen ingredient are discussed.     

Frozen State Transitions in Freeze-Concentrated Lactose-Protein-Cornstarch Systems

Differential scanning calorimetry study of frozen state transitions of mixtures of lactose, proteins, cornstarch, and water revealed that maximum freeze-concentration was achieved by annealing at temperatures T′_m-1. The onsets of glass transition of maximally freeze-concentrated solids, T′_g, were lower and onsets of ice melting, T′_m, were higher for mixtures of proteins and polysaccharide than those of lactose. The established state diagrams showed solids concentrations C′_g, of the maximally freeze-concentrated systems of, 82, 78, 78, 78, and 75% for lactose, lactose/albumin, lactose/gelatin, lactose/cornstarch, and lactose/cornstarch/gelatin solutions, respectively. The state diagrams established with experimental and predicted T_g values are useful in characterization of thermal phenomena and physical state of the systems at various water contents and in the freeze-concentrated state.     

Selected Physical Properties of Lime Bee Honey in Order to Discriminate Between Pure Honey and Honey Adulterated with Glucose

The refractive index, conductivity, optical rotation, thermophysical parameters, and infrared spectra of bee honey samples, as well as the content of β-carotene and potassium, were determined with a view to discriminate between pure honey and honey adulterated with glucose. The glass transition temperature and the optical rotation may be used for qualitative assessment of honey adulteration with glucose. Another indication of lime honey adulterated with glucose was the β-carotene content below 20 ppm and the potassium content below 200 ppm. The minimum detectable amount of glucose adulterant was 25 g in 100 g honey.     

Assessment of physical properties of fibres from thermoplastic polymers by means of tensiometric tests

Several properties of fibres and monofilaments made from polymers such as polyamide 6 (PA), poly(ethylene terephthalate) (PET), polypropylene (PP), aliphatic polyester of butanediol, succinic and adipic acids (PBSA), aliphatic-aromatic polyester of butanediol, terephthalic and adipic acids (PBTA) have been studied. Wettability of monofilaments has been tested by dynamic contact angle method, so surface free energy of synthetic fibres could be calculated. A tensiometer was used for testing the fibre-to-fibre friction coefficient, Young's modulus and bending modulus. It was found that the surface properties of fibres from synthetic polymers such as surface free energy, moisture absorption, and friction coefficient are related to the physical as well as physical–chemical properties, elasticity, elongation, thermal shrinkage and glass transition temperature. The good coherence of the tests performed with the theoretical relationship between Young's modulus of fibres and glass transition temperature of fibre-forming polymers clearly and definitely verifies the experimental results.     

Effect of water uptake on amorphous inulin properties

Physical property changes of amorphous spray-dried inulin were investigated during water uptake at 20 °C. Modulated Differential Scanning Calorimetry (MDSC) and Wide Angle X-ray Scattering (WAXS) were used to investigate the evolution of the glass transition temperature (T_g) and the crystallinity index, respectively. The water content, crystallization and thermal properties relationship enabled the identification of three zones in the T_g–water content state diagram. Zone I delimited inulin in a glassy amorphous state, while zone II characterized inulin in a liquid amorphous state. Inulin crystallized and caked when T_g was below the storage temperature of 20 °C, but crystallization (zone III) was not spontaneous and was delayed by the defined zone II. The crystallization led to thermograms with an endotherm close to T_g. Temperature-Resolved WAXS allowed to correctly ascertain the MDSC endothermic peak as a melting peak because the crystallinity index was maximal at onset temperature of the transition, and dropped to zero at the endset temperature.     

口香糖用聚醋酸乙烯酯的合成

采用悬浮聚合法合成口香糖用聚醋酸乙烯酯树脂，研究了ＰＶＡＣ的分子量与分散剂用量，分子量调节剂用量、引发剂用量的关系，测定了不同分子ＰＶＡＣ的玻璃化温度。结果表明，ＰＶＡＣ的分子量是可以调节的。Ｔｇ随着分子量的增大而提高。     

Fleece Production,Scouring Yield,and Down Hair Yield of Tunisian Dromedary

The results show that the greasy fleece weight varied from 0.3 kg to 2.42 kg with an average of 0.75 kg. The fleece weight decreases according to the animal age. In fact, the factor “age” has a significant effect on the dromedary fleece weight. Average scoured yield was 96% with V% of 1.6%. This indicated that matter loss, after scouring dromedary fibres, was lower than wool and cashmere. Scoured yield did not vary between samples of varied dromedary body areas in any age. The down hair yield for the fleece of the Tunisian dromedary varies between 34% and 61% with a mean of 45%. This raises interest when compared to the cashmere yield. There is a clearly decreased dromedary down hair yield according the factor “age”. The analysis of the variance shows that the dromedary down hair yield was affected by the factors “age” and body area of the animal.

Following this work it will be possible to predict the amount of down yield in the fleece of Tunisian dromedary knowing age. Consequently, it will be possible to estimate the total amount of textile material camel from dromedary located in Tunisia.     

Bioactive compounds in bamboo shoots: health benefits and prospects for developing functional foods

Juvenile bamboo shoots have long been used as food and in traditional medicine in many Asian countries, but scientific evidences of its health benefits have been highlighted recently. According to ancient Chinese medicinal books, the consumption of young shoots helps in improving digestion, relieving hypertension, sweating, preventing cardiovascular diseases and cancer. The young shoots are delicious and rich in nutrient components such as proteins, carbohydrates, minerals and vitamins and bioactive compounds. The health benefits of the young shoots are attributed to the presence of bioactive compounds mainly phenols, phytosterols and dietary fibres, which play a potential role in health promotion and providing protection against many chronic and degenerative diseases. Phenolic compounds in bamboos have multiple biological effects such as antioxidation, anti‐ageing, antifatigue, antimicrobial and prevention of cardiovascular diseases. Dietary fibres and phytosterols have a beneficial effect on lipid profile and bowel function and reduce total serum cholesterol and low‐density lipoprotein cholesterol level. This study discusses the bioactive compounds in bamboo shoots and how, due to its nutritive value and health benefits, the shoots can be utilised as an ingredient in the development of functional foods.