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Fatty acid content of raw and cooked zander (Sander lucioperca) was studied. Special attention was paid to long-chain polyunsaturated fatty acids: eicosapentaenoic, 20:5 n-3 (EPA) and docosahexaenoic, 22:6 n-3 (DHA), and also to the n-6/n-3 ratio, which are regarded as indicators of nutritive value. As found, the heat treatments, boiling, stewing and frying, including those in a convection steam oven (CSO), did not significantly decrease the content of EPA and DHA in the products. Boiling and stewing appeared to give products of a higher nutritive value, regarding the above indicators, than frying and cake preparation. Frying of zander in CSO was found to be more beneficial for nutrition compared to pan-frying. The cooked zander had higher EPA and DHA contents than many other popular food fish species, and also had a high nutritive value due to the low n-6/n-3 ratio when boiled and stewed.

The aim of this study was to examine the effect of power ultrasound on the allergenicity and texture properties of shrimp (Penaeus vannamei). For this purpose, raw and boiled shrimps were treated with power ultrasound (30 kHz, 800 W) at 0 deg C and 50 deg C for 0, 2, 8, 10, and 30 minutes. The results showed that the ultrasound treatment had a greater effect on the allergenicity of the boiled shrimps than of the raw ones, while with hardness it was vice versa. The allergenicity of the boiled shrimps treated at 0 deg C (treatment 3) and 50 deg C (treatment 4) decreased by nearly 50% and 40%, respectively, with 10 min of the treatment duration. As for the raw shrimps, with the treatment at 0 deg C (treatment 1), their allergenicity increased in the first 10 min and then decreased, while at 50 deg C (treatment 2), a slight reduction of 8% in allergenicity occurred. After treating with ultrasound for 30 min, the hardness in treatment 1 increased to a peak-1.5-fold higher than the control, compared with 27% increase in treatment 2 and 15% increase in treatments 3 and 4. The results suggest that allergenicity can be reduced by power ultrasound with no change in the texture.

Headspace solid phase microextraction and purge and trap analysis were used for the determination of volatiles in beer. These methods were compared with the analysis of unconcentrated gas phase and liquid extraction. Solid phase microextraction proved to be the most useful and was investigated more closely. Volatiles were isolated by the means of different combinations of sorbents, sorption was performed at various temperatures and times. The addition of salt to the sample and stirring of the sample were examined to enhance the analyte concentration in the gas phase. Ultrasonic bath and filtration were tested to remove carbon dioxide. Not all methods improved the sorption of volatiles. Stirring was characterised by low repeatability and ultrasonic bath causes to the loss of volatile analytes. Distribution constants of volatiles depend on their boiling points and thus different sorption temperatures are suitable for different substances.

Some coffee brewing techniques raise the serum concentration of total and low-density-lipoprotein cholesterol in humans, whereas others do not. The responsible factors are the diterpene lipids cafestol and kahweol, which make up about 1% (wt:wt) of coffee beans. Diterpenes are extracted by hot water but are retained by a paper filter. This explains why filtered coffee does not affect cholesterol, whereas Scandinavian \"boiled,\" cafetiere, and Turkish coffees do. We describe the identification of the cholesterol-raising factors, their effects on blood levels of lipids and liver function enzymes, and their impact on public health, based on papers published up to December 1996

Quality Protein Maize (Zea mays) (QPM) varieties have been developed by scientists at the Institute of Agricultural Research and Training in Nigeria. For these varieties to have significant impact, they must possess traits acceptable to farmers. A study was carried out to evaluate the agronomic and sensory traits of two Quality Protein Maize - ART-98-SW-6-OB (QPM1) and ILE-1-OB (QPM2), in comparison with ART-96-SW-1 (High Protein Maize) and SUWAN-1-SR (a popularly grown improved variety) in three maize growing communities of South West, Nigeria. Sixty (60) farmers comprising males and females were evaluated for six sensory parameters. The parameters tested were appearance, colour, flavour, texture, taste and overall acceptability. The results of the agronomic evaluation showed that there were no significant differences in the height of QPM varieties and HPM at harvest. QPM varieties gave the highest grain yield of 2.38t/ha for ART-98-SW-6OB and 2.36t/ha for ILE-1-OB. Sensory evaluation showed that when the maize varieties were processed into corn-soy milk, QPM corn-soy milk had the highest sensory scores for all sensory parameters tested. Quality Protein Maize varieties had high grain yield and were most preferred for maize pudding and corn-soy milk. The QPM varieties, if formulated into foods for household or commercial purposes, should have good chance of being accepted by farmers with continuous promotional campaigns.

The influence of boiling time (10 -120 min) on nutritional and antioxidant properties of Lentinus edodes pieces and broth was investigated. The results showed that the primary nutrients contents and antioxidant activities of L. edodes pieces decreased with the prolongation of boiling time, while ergosterol content increased. The nutrients contents in L. edodes broth presented an uptrend, and the antioxidant activities increased rapidly in the first 30 min, and then kept stable or decline, which was positively correlated with the change of total phenolic content. Microstructure observation showed that boiling treatment destroyed the cell wall of L. edodes, leading to the dissolution and loss of cell wall components and cytoplasmic contents. From the point of nutrition, the optimal boiling time for L. edodes pieces is 30 min and for broth preparation is 60 min. This study provides a useful reference for rational cooking or processing L. edodes and other mushrooms.

This study examined how boiling and drying treatments influenced various physical properties of the tension wood with gelatinous fibers (G-fibers) of a 29-yearold Zelkova branch. By boiling treatment, tension wood with numerous G-fibers contracted considerably in the longitudinal direction and the longitudinal Young’s modulus decreased in spite of the water-saturated condition. The drying treatment caused green tension wood and boiled tension wood with numerous G-fibers to shrink longitudinally and increased their longitudinal Young’s moduli. These specific behaviors in tension wood were highly correlated with the proportion of G-fibers in a specimen and were probably caused by the microscopic behavior of cellulose microfibril (CMF) in the gelatinous layers (G-layers). The longitudinal shrinkage of tension wood due to drying suggests the existence of a hygro-sensible, noncrystalline region in the CMF, which is abundant in the G-layer. Furthermore, the noncrystalline region in the CMF softens during boiling treatment, resulting in the reduction of the longitudinal Young’s modulus in tension wood. The longitudinal contraction of tension wood with G-fibers by boiling might be caused by the tensile growth stress remaining in green G-layers. However, no changes were detected in the 004 d-spacing of cellulose crystal in tension wood from the boiling and drying treatments, regardless of the proportion of G-fibers.

:  There is concern regarding a possible decrease in the minimum exploitable size of the mantis shrimp Oratosquilla oratoria in Tokyo Bay, coincident with a decline in stock size. To assess this problem, the condition factor, the relationship between body length and processed‐meat length, and the estimated body length for each market size category were investigated and compared monthly. The condition factor was lowest in spring and peaked in winter. The difference between body length and meat length was higher in summer and winter than in spring and autumn, suggesting that a high condition factor does not result in an increased net yield of processed meat. The annual mean minimum exploitable size in the present low‐stock‐size condition did not differ from the minimum exploitable size measured during a high‐stock‐size period (11‐cm body length). However, the minimum exploitable size changed seasonally, which coincided with seasonal change in the net processed‐meat yield. Exploitation during the season when net meat yield is high would result in increase of the large‐sized meat products of high price.

HPLC method for 5-methyltetrahydrofolate (5-MTHF) determination in vegetables was optimised for the folate release from the food matrix. Enzymatic hydrolyses using the subsequent addition of alpha-amylase, protease, and conjugase from hog kidney, or their combinations, were tested. The highest release values were obtained with the application of alpha-amylase and conjugase, amounting to 112.4-127.0% of the values obtained in the processing with the conjugase alone. The simultaneous addition of both enzymes and the incubation at pH 4.9 did not suppress the release of folates. Spinach, Chinese cabbage, lettuce, cauliflower, and broccoli contained more than 50 microg of 5-MTHF/100g, whereas less than 25 microg/100 g was found in potatoes, carrot, white cabbage, green and yellow pepper. Individual vegetables differed in the folate retention during their boiling under constant conditions. The highest retention was found in Brussels sprouts, cauliflower, and broccoli. After 8 min boiling more than 75% of the initial amount of 5-MTHF remained in these vegetables. Lower values of 5-MTHF retention (between 37% and 52% of their initial content) were found in spinach, savoy cabbage, and carrot.