Advanced Materials Research Vols. 634-638

Abstract: Commercial crude tea saponin as raw material, ultrasonic assisted extraction technology of tea saponin was investigated. Five influence factors of ethanol concentration, extraction temperature, extraction time, solid-liquid ratio, ultrasonic power on the extraction of tea saponin were studied in detail. Orthogonal experiment through the single factor experiment design, the experimental results show that the optimum operating conditions for the ethanol concentration of 80%, solid-liquid ratio 1: 40, extraction temperature 40°C, ultrasonic power of 300W, ultrasonic extraction time 45 minutes. Under the optimum conditions obtained tea saponin extract with ethanol- acetone precipitation method is further purified, tea saponin content increased from 52.1% to 93.6%. The result indicated that the purity of the tea saponin could be effectively improved through the ultrasonic assisted- precipitation combined method.

Abstract: The effect of different washing treatments on the gelatin properties and quality characteristics of grass carp surimi was studied. Distilled water, 0.5% NaCl, 0.5% NaHCO3, 0.6% CaCl2 and a mixture of 0.1% NaCl and 0.2% NaHCO3 were used for washing minced meat of grass carp. The effects on moisture, protein, fat, expressible moisture, whiteness and gel strength were analyzed. Moisture content increased while fat and protein decreased after each washing treatment. The maximum moisture increase was 6.54% which was found in the surimi washed with 0.1% NaCl and 0.2% NaHCO3. When the sample was washed using 0.5% NaHCO3, moisture content increased by 1.66%. Compared to unwashed grass carp surimi, the whiteness and expressible moisture were improved effectively using different washing treatments. The highest whiteness was found using 0.6% CaCl2. Only when 0.6% CaCl2 solution was used for washing, the gel strength of surimi improved.

Abstract: Volatiles of maca in vitro could be captured by way of dynamic head-space adsorption. Both maca root and leaf volatile compounds were different from essential oil or other extracts. In the root volatiles, isothiocyanates were in the highest content (27.26%), especially 4-ethylphenyl isothiocyanate over 20%. Together with chloro-compounds (near 20%) and tetrahydro-3-methylfuran (14%), the three types of chemicals were probably important factors of maca’s special odor like other vegetables of Brassicaceae. And in the leaf volatiles, the highest contents (about 30%) were found in acid and anhydride. Compared to maca essential oil, ester (<5%) and terpene (<1%) in the volatiles both from root and leaf were not the same compounds.

Abstract: 31 Functional components of polished and brown rice and 50 SSR markers fingerprint for boro groups collected from 41 farmers from two village in Xinping county were investigated. The results as follows: We have bred first from rice landrace that Gongmi No. 3 with the highest resistant starch in the world, its resistant starch content of uncooked and cooked of polished rice are 8.0%~8.5% and 10%~13% respectively; meanwhile constructed the DNA fingerprinting of Xinpingzaoxian and Gongmi No.3 with high resistant starch based on 50 SSR markers. The cooked Xinpingzaoxian were steaming again and air-dried,then the resistant starch content were up to 12.2%; At present, Gongmi No.3 is the most ideal rice products to prevent chronic diseases in the World, especially for diabetes. The total amino acids, 4 amino acids and sulfur elements of brown and polished rice for Xinpingzaoxian with high resistant starch, which relatively distribute evenly in scytoblastema and endosperm, but 5 amino acids are unevenly distributed. Iron and zinc content of polished rice is 5.55% and 21.21% of brown rice, respectively.

Abstract: Monitoring of heavy metals in consumer products is essential in order to aid in the production of safer food commodities for the Filipino public. Ten canned fruits commercially available in Metro Manila, Philippines were randomly selected for the study. Five brands of canned fruits of Prunus persica (peaches), three of Litchi chinensis (lychees) , and two of Ananas comosus (pineapple) were tested for lead, cadmium and chromium levels. The fruit and syrup portions were separately tested quantitatively for the said heavy metals through Flameless Atomic Absorption Spectroscopy. Chromium was found to be present in nine out of the ten syrup samples from the canned fruits while cadmium is present in one syrup sample of canned peaches. All the amounts of the heavy metals were in acceptable chromium and cadmium levels for consumption. Lead was observed to be present in acceptable values in the solid fruits of all samples analyzed. Four syrup samples showed lead levels with the syrup from peaches exceeding the allowed safe limit. The rest of the syrup samples went below the detection limit of the instrument. Higher number of canned fruits and other canned products in the market must be analyzed with regard to lead, cadmium and chromium to complete the baseline data related to contaminants in these products for consumer safety.

Abstract: Aims: To optimize the culture media of 0288 Tricholoma matsutake and to identify it according to its rDNA ITS sequence. Methods: Fruit body, collected from Heilongjiang province, is used as the material, and the mycelium is isolated and radiated under ultraviolet. Then the radiated mycelium is cultured in five different media and its morphology of fungus colony and growth rate are investigated. After that, the rDNA ITS sequences of 0288 and the natural fruit body of T. matsutake are analyzed and identified by PCR and sequencing. Results: The radiated mycelium grew faster in formula A culture medium than others and its average growth rate is up to 0.575mm/d. Results also showed that the homology of the rDNA ITS sequence is almost up to 99% between 0288 and the natural fruit body. Through this experiment, the best growth condition of 0288 is obtained and its fruit body is induced as pure cultural product. It would lay strong foundation for the artificial domestication of the wild T. matsutake.

Abstract: Heavy metals are considered harmful contaminants of food, previously recognized to pose both health and environmental hazards. Junk food are considered an everyday food of the general public most especially by children. There are no studies yet describing the heavy metal contents of junk food thus the primary objective of this study is to address such concerns. This study analyzed the heavy metal contents lead, cadmium, and chromium of 36 junk food, through Flame Atomic Absorption Spectroscopy. Lead values ranged from 8.5398 to 0.0093 ppm while cadmium ranged from non detectable to 0.0085 ppm and for chromium, ranged from 0.1261 to 0.3106 ppm. It was observed that the sample Princess Snack’s lead content was significantly higher than the allowable limit for lead. The said product is imported from a country in East Asia. In conclusion, all samples obtained showed low amounts of cadmium while almost all samples contained lead except for one while for chromium all samples have content way above the safety limits. It is recommended that more studies should be done in samples that have not passed in terms of their heavy metal limits.

Abstract: A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min^-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg^-1 and 5 μg•kg^-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg^-1 spiking levels range from 77.4% to 95.3%. The ^{SupersSuperscript textcript text}relative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.

Abstract: The extraction of capsaicin from chili pepper powder by microwave-assisted technique has been investigated in a microwave chemical synthesis instrument. Orthogonal test was conducted on the basis of single-factor experiment. The parameters used for the optimization were solid-liquid ratio, extraction time and extraction temperature. The capsaicin was quantified by UV/Vis spectrophotometric determination. The influence of three factors on the extraction yield of capsaicin from chilli by microwave method decreases in the order: temperature> solid-liquid ratio>time. The optimum extraction conditions are at 120°C and solid-liquid ratio of 25mg/mL for 90-min. Under this condition，the extraction yield of capsaicin is 3.85%.

Abstract: In recent years, due to the ultra-fine powder is widely used in various industries of the national economy. And corresponding to domestic and foreign have developed a variety of ultra-fine grinding equipment, including stirring mill, which is considered the most potential for development of an ultra-fine grinding equipment. This is brought to its unique working principle and structure characteristics. This paper introduces the stirred mill work principle as well as the history of the development of the stirred mill both at home and abroad, which analysis of the structural characteristics of stirred mill. And it puts forward the directions of the stirred mill in the future research.