ANTIOXIDATIVE FLAVONOID GLYCOSIDES FROM QUINOA SEEDS (CHENOPODIUM QUINOA WILLD)

Six flavonol glycosides have been isolated from quinoa seeds ( Chenopodium quinoa Willd) via normal phase and reverse phase column chromatography. On the basis of spectral data, their structures were established as kaempferol 3-O-[β-D-apiofuranosyl(1'–2")]-β-D-galactopyranoside ( 1 ), kaempferol 3-O-[α-L-rhamnopyranosyl(1"–2")]-β-D-galactopyranoside ( 2 ), kaempferol 3-O-[β-D-apiofuranosyl(1'–2")-α-L-rhamnopyranosyl(1"–6")]-β-D-galactopyranoside ( 3 ), kaempferol 3-O-(2,6-di-α-L-rhamnopyranosyl)-β-D-galactopyranoside ( 4 ), quercetin 3-O-[β-D-apiofuranosyl (1'–2")-α-L-rhamnopyranosyl(1"–6")]-β-D-galactopyranoside ( 5 ) and quercetin 3-O-(2,6-di-α-L-rhamnopyranosyl)-β-D-galactopyranoside ( 6 ). Among them, compounds 1, 4 and 6 were the main flavonoid glycosides found in quinoa seeds and compounds 2, 5 , and 6 were isolated from this plant for the first time. All six compounds exhibited antioxidant     

超声强化提取人参皂甙过程中声学参数的选择

研究了在超声强化提取人参皂甙过程中，一些声学参数（声强、频率、时间、作用方式等）对皂甙得率的影响。结果表明：皂甙的得率是随着声强的提高而增长，在1．28W／cm^2这样的低场强的条件下，随着频率的增长而减少，在2．55W／cm^2场强的条件下，随着频率的增长先增长后减少，随着超声作用时间的延长而提高。超过1h后则提高的趋势已不太明显。另外还对比得出中央浸入式处理器中的皂甙得率高且能量利用率也较高，宜于在规模化生产实验中推广应用。     

DEVELOPMENT OF A CONTINUOUS METHOD FOR PUFFING AMARANTH (AMARANTHUS SPP.) SEEDS

Amaranth ( Amaranthus spp.) is a nutritionally dense pseudocereal grown mostly in South America and Asia. Traditionally amaranth seeds are puffed using a hot skillet. Besides being a batch system, in this process there is little control over the temperature and the residence time of the seeds. We have developed a continuous technique for puffing amaranth seeds using a single-screw extruder with a tapered screw without a die. With this technique we could control the temperature and the residence time for puffing the seeds. It was found that the puffing efficiency of amaranth seeds was a function of temperature and screw speed. The maximum efficiency of 86% was achieved at a barrel temperature of 290C and screw speed of 125 rpm. Sensory analyses with an untrained panel of 33 subjects using samples generated at conditions with puffing efficiency above 75% showed that the sample processed at 250C and 75 rpm was the most acceptable in terms of various sensory attributes and overall liking.

PRACTICAL APPLICATIONS

The research aims to develop a new continuous process for the puffing of amaranth seeds. The use of an extruder without a die for puffing these seeds is a novel idea. This process could possibly be used for puffing several other seeds and grains, making it a versatile technology. The sensory work conducted in this paper aims at examining the acceptance of this relatively new product among U.S. consumers.     

BIOCHEMICAL CHARACTERIZATION OF BORAGE (BORAGO OFFICINALIS L.) SEEDS

Gas chromatography–mass spectrometry analysis of seed Borago officinalis essential oil (EO) revealed the presence of 16 volatile components. β-Caryophyllene (26%) and p-cymene-8-ol (19.7%) represented the major components, while nonadecane (0.7%) and hexanol (0.7%) were the minor ones. The EO composition was characterized by higher abundance of oxygenated monoterpenes (27.7%), followed by sesquiterpenes (26%). Fatty acid composition showed the predominance of linoleic (35.4%), oleic (24.2%) and γ-linolenic (20.4%) acids. Polyphenols were analyzed by reversed-phase high-performance liquid chromatography after acid hydrolysis of phenolic acid esters. Six phenolic acids were identified in seed extract and rosmarinic acid was the predominant one with 1.65 mg/g dry matter weight equivalent to 33% of total phenolic acids.

PRACTICAL APPLICATIONS

Borage ( Borago officinalis L.) is of great interest because of its medicinal and nutritional properties. In fact, thanks to its characteristic composition in fatty acids, particularly high levels of gamma-linolenic acid in its seed oil, borage has gained importance. The potent consumers of this medicinal plant are hypertensive and hypercholesterolemic people. Borage consumption is also recommended for people suffering from rheumatism and eczema.
Unfortunately, the knowledge about antioxidative/antiradical properties of borage is very scanty. So, recently, an extensive investigation was focused on the antioxidant properties of borage extracts. These extracts showed excellent antioxidant properties and their effects were attributed to their phenolic constituents. These antioxidants can be concentrated, either as crude extracts or individual phenolic compounds, to be used in highly unsaturated oils such as marine oils. Furthermore, borage consumption has been reported as a possible gastric cancer protective factor.     

A NEW APPROACH TO CORRELATE TEXTURAL AND COOKING PARAMETERS WITH OPERATING CONDITIONS DURING DOUBLE-SIDED COOKING OF MEAT PATTIES

Cooking and textural parameters during double-sided cooking of hamburger patties were correlated with volume-averaged temperature at the end of the cooking process and gap thickness between plates. Frozen patties were cooked in a clamshell grill set at different plate surface temperatures (177C; 191C; 204C; 218C), for different gap thicknesses (9.65 mm; 10.55 mm; 10.55 mm; 11.05 mm) for 120 s. A decrease in the gap thickness and an increase in the plate surface temperature resulted in an increase in the cooking loss values (24–36%) and in a decrease of press juice values (8–25%). The values of peak load (183–215 N), modulus (16–19 N/mm), work needed in shearing (2300–2800 Nmm), hardness (25–32 N), cohesiveness (0.76–0.83), and chewiness (107–152 Nmm) of the patties increased when the gap thickness decreased and the plate surface temperature increased. There was no effect of the variables studied on springiness. The correlation equations involving the operating variables and quality parameters obtained are simple and useful in developing optimal process conditions.     

A KINETIC STUDY OF THE SUSCEPTIBILITY TO ENZYMIC HYDROLYSIS OF STARCH IN MALT

Finely-ground malt was held in suspension in water for various times at given temperatures and measurements were then made of the susceptibility of starch to enzymic hydrolysis. The results were used to determine first-order rate constants for the process of conversion of starch to the susceptible form. The variation of rate constant with temperature was satisfactorily described by the Arrhenius relationship with an activation energy of 8·06 × 10⁴ cal/mole and a frequency factor of 6·73 × 10⁵³ min^?1. The variation of the extent of conversion with temperature was adequately described by a cumulative normal relationship with a mean of 49·8°C and a standard deviation of 5·79°C.     

A NUMERICAL APPROACH WITH VARIABLE TEMPERATURE BOUNDARY CONDITIONS TO DETERMINE THE EFFECTIVE HEAT TRANSFER COEFFICIENT VALUES DURING BAKING OF COOKIES

The increasing trade of ready‐to‐eat foods such as cookies highlights an interest in quality defects during baking. Heat (h and thermal diffusivity) and mass (mass transfer and diffusion coefficients) transfer parameters are significant parameters affecting the quality changes. Therefore, it is important to determine these parameters for modeling and process optimization studies. Among these, the h is important, revealing the relationship between the heating medium and product surface. As baking involves a simultaneous heat and mass transfer involving moisture diffusion and heat conduction inside and convective heat and mass transfer outside, a lumped system method may not be an accurate choice to determine the h value. Changes in the product volume and contact heating from bottom of the product also bring extra challenges to the determination of h. Therefore, the objective of this study was to use realistic approaches including simultaneous heat and mass transfer to determine the changes in h. The h_effvalues for the bottom and top surface of the cookies were then determined, applying a numerical procedure where the surface temperature changes were the boundary conditions with evaporation on the surface. The h_band h_t values increased with baking temperature and varied with baking time. The results of this study showed that evaporative mass flux for the top surface, heat flux for the bottom surface and the product's volume changes were significant in the variation of h values.     

LIPOLYTIC ACTIVITY OF ENZYMES FROM GERMINATING SEEDS OF SESAME (SESAMUM INDICUM L.)

Sesame ( Sesumum indicum ) seeds were germinated for seven days under laboratory conditions and the lipolytic activity of the defatted, dried seedlings was determined. Germination increased the lipolytic activity of sesame seeds and the highest activity was observed on day-4. The lipases of four days germinated sesame seeds were able to hydrolyze mainly the saturated fatty acids from seal blubber oil (SBO). Reaction temperature, incubation period and oil-to-seedling powder ratio had a significant effect on the hydrolysis of saturated fatty acids, thereby concentrating unsaturated (mono- and polyunsaturated) fatty acids of seal blubber oil.     

A PRACTICAL APPROACH TO THE ASSESSMENT OF HEAD RETENTION OF BOTTLED BEERS

A method is described for the assessment of the head retention of bottled beers. The technique enables three aspects of head retention (head formation, adhesion and collapse rate of the foam) to be simultaneously determined. The procedure consists of the shock injection of a small volume of carbon dioxide under pressure into a known volume of beer, previously introduced without fobbing into a specially-calibrated glass vessel, followed by measurements at stated intervals on the foam so produced. The apparatus is simple and inexpensive and a determination can be completed in 7–8 min. Some results for bottled beers are discussed in respect of bottle-to-bottle differences; the effect on head retention of storage and of the use of wheat flour in the grist has also been examined. It is claimed that the method gives results which are more informative than those defined by a single factor such as half-life and are more in line with consumer judgement.     

超临界CO2萃取海金沙中黄酮的研究

通过单因素和正交试验研究，对超临界CO2流体萃取海金沙黄酮类化合物的工艺进行了优化设计。试验结果表明，影响萃取得率的各因素大小顺序是：萃取温度〉萃取压力〉流体流量〉萃取时间；本试验确定最佳萃取试验工艺条件为：萃取温度45℃，萃取压力25MPa，流体流量3．0L／h，萃取时间3h。     

Fe(Ⅱ)-磺基荧光酮-CTMAB三元络合物间接分光光度法测定织物的甲醛含量

在碱性条件下，甲醛与水合氧化银发生氧化还原反应，生成的银定量还原Fe(Ⅱ)为Fe(Ⅱ)，Fe(Ⅱ)与磺基荧光酮在CTMAB存在下形成三元络合物、利用分光光度法测定该络合物以间接测量织物的甲醛含量，该法是测定织物中甲醛量的一种简便、灵敏的新方法。