Journal of the Science of Food and Agriculture
1097-0010
0022-5142
Anh Quốc
Cơ quản chủ quản: WILEY , John Wiley and Sons Ltd
Lĩnh vực:
Food ScienceNutrition and DieteticsBiotechnologyAgronomy and Crop Science
Các bài báo tiêu biểu
Phenols in smoked cured meats. Phenolic composition of commercial liquid smoke preparations and Derived Bacon Abstract The phenolic composition of two commercial liquid smoke emulsions has been determined by gas chromatography‐mass spectrometry of the free phenols and their trimethylsilyl ethers. The phenolic fraction of smoked bacons derived from the liquid smoke emulsions has been determined similarly and compared with the phenolic fraction of traditional kiln‐smoked bacon. A preliminary examination of phenol penetration in smoked bacon has been made on a sample prepared from a liquid smoke emulsion by electrostatic spraying.
Tập 26 Số 2 - Trang 189-196 - 1975
Increase of the adhesion ability and display of a rumen fungal xylanase on the cell surface of <i>Lactobacillus casei</i> by using a listerial cell-wall-anchoring protein
Tập 94 Số 3 - Trang 576-584 - 2014
Changes in physicochemical and nutritive parameters and bioactive compounds during development and on‐tree ripening of eight plum cultivars: a comparative study Abstract BACKGROUND: There is no literature on changes in organoleptic, nutritive and functional properties during plum development and on‐tree ripening. In this work a comparative study on the evolution of physical, chemical and nutritive parameters and bioactive compounds of eight plum cultivars (yellow and dark‐purple) was performed.RESULTS: The main changes related to ripening (colour, total soluble solids, acidity, firmness and bioactive compounds) started at the early stages of fruit development, with significant differences among cultivars. Colour hue angle was highly correlated with increase in anthocyanins or carotenoids (in both skin and flesh). Total antioxidant activity (TAA) was determined in the hydrophilic (H‐TAA) and lipophilic (L‐TAA) fractions separately, and values were always higher in the skin than in the flesh. A continuous increase in both H‐TAA and L‐TAA during the process of ripening occurred. H‐TAA was about twofold higher than L‐TAA in the dark‐purple cultivars, while the opposite was found in the yellow cultivars. In addition, H‐TAA was correlated with total phenolics and total anthocyanins, while L‐TAA was positively correlated with total carotenoids.CONCLUSION: In order to achieve the optimal organoleptic, nutritive and health‐beneficial properties of plum consumption, it would be advisable to harvest the fruits at the fully ripe stage. Copyright © 2008 Society of Chemical Industry
Tập 88 Số 14 - Trang 2499-2507 - 2008
Effect of initial oxygen concentration and film oxygen transmission rate on the quality of fresh‐cut romaine lettuce Abstract Modified atmosphere packaging (MAP) is widely used to maintain the quality of fresh‐cut produce by matching the oxygen transmission rate (OTR) of the packaging film to the respiration rate of the packaged product. The effect of the interaction between film OTR and the initial headspace O2 on quality of fresh‐cut vegetables has not previously been reported. Romaine lettuce leaves were sliced, washed, dried and packaged with film OTRs of 8.0 and 16.6 pmol s−1 m−2 Pa−1 , and with initial headspace O2 of 0, 1, 2.5, 10 and 21 kPa. Packages were hermetically sealed and stored at 5 °C for up to 14 days. For samples packaged in 16.6 OTR film, increasing the initial headspace O2 concentration delayed O2 depletion within the packages, hastened the onset and increased the intensity of discoloration, and inhibited the development of CO2 injury, acetaldehyde and ethanol accumulation, off‐odors and electrolyte leakage. With 8.0 OTR‐packaged lettuce pieces, ≤1 kPa initial headspace O2 treatments induced an essentially anaerobic environment within the packages and increased acetaldehyde and ethanol accumulation and off‐odor development. Increasing the initial O2 concentration above 1 kPa in 8.0 OTR packages transiently increased O2 concentrations and reduced fermentative volatile production, off‐odors, electrolyte leakage and CO2 injury. Regardless of initial headspace O2 concentration, all 16.6 OTR‐packaged samples had severe discoloration after 14 days of storage. Quality was better maintained in 8.0 OTR‐packaged lettuce pieces as the initial headspace O2 concentration was increased. A 21 kPa initial O2 treatment of 8.0 OTR‐packaged lettuce maintained good quality throughout storage and had the best overall quality score. Copyright © 2005 Society of Chemical Industry
Tập 85 Số 10 - Trang 1622-1630 - 2005
Recycling slaughterhouse waste into fertilizer: how do pyrolysis temperature and biomass additions affect phosphorus availability and chemistry? Abstract BACKGROUND Pyrolysis of slaughterhouse waste could promote more sustainable phosphorus (P) usage through the development of alternative P fertilizers. This study investigated how pyrolysis temperature (220, 350, 550 and 750 °C), rendering before pyrolysis, and wood or corn biomass additions affect P chemistry in bone char, plant availability, and its potential as P fertilizer. RESULTS Linear combination fitting of synchrotron‐based X‐ray absorption near edge structure spectra demonstrated that higher pyrolysis temperatures decreased the fit with organic P references, but increased the fit with a hydroxyapatite (HA ) reference, used as an indicator of high calcium phosphate (CaP ) crystallinity. The fit to the HA reference increased from 0% to 69% in bone with meat residue and from 20% to 95% in rendered bone. Biomass additions to the bone with meat residue reduced the fit to the HA reference by 83% for wood and 95% for corn, and additions to rendered bone by 37% for wood. No detectable aromatic P forms were generated by pyrolysis. High CaP crystallinity was correlated with low water‐extractable P, but high formic acid‐extractable P indicative of high plant availability. Bone char supplied available P which was only 24% lower than Triple Superphosphate fertilizer and two‐ to five‐fold higher than rock phosphate. CONCLUSION Pyrolysis temperature and biomass additions can be used to design P fertilizer characteristics of bone char through changing CaP crystallinity that optimize P availability to plants. © 2014 Society of Chemical Industry
Tập 95 Số 2 - Trang 281-288 - 2015
The relation between yield and protein in cereal grain Abstract An analysis of published data on genetic relations between dry grain yields (y, t ha−1 ) and protein content [p , protein as a fraction (g g−1 ) of dry grain] of cereals is presented. In all, 106 usable regressions of y on p across geneotypes were assembled. The long‐recognised negative relation between yield and protein concentration was fully substantiated. There is a strong positive relation between grain yield and protein yield. The linear regression coefficient of yield on protein concentration is related to yield, with slope about −15. This relation holds approximately over all cereals. The data can be used to estimate a characteristic parameter described by C = dy/d(yp ) = ∼ 15–25 at the mean of each experiment. The relationship is surprisingly consistent but no simple physiological interpretation is available. In discussion, the high C , the impact of strong negative regressions of y on p for breeding strategies, the fact that protein yield increases with gross grain yield but at falling p and certain socio‐economic consequences are emphasized. An acute need for orderly reporting of experimental data is also emphasised; the existing literature is chaotic as to units, moisture contents and conversion factors.
Tập 67 Số 3 - Trang 309-315 - 1995
Colorimetric determination of sugars in sweetened condensed milk products Abstract Two means for determining the lactose and sucrose contents of sweetened condensed milk products are examined. The first of these is a simple calculation based on polarimetric measurements and gives reproducible results for lactose which agree well with conventional methods of determination. The second is a novel colorimetric method based on determination of total carbohydrate before and after degradation of lactose with alkali. This gives slightly higher values for lactose in sweetened condensed milk products than conventional methods but could nevertheless be adopted as a means of analytical control, due to its speed, simplicity and cheapness. The advantages and disadvantages of both techniques are compared with those of conventional analytical methods.
Tập 25 Số 11 - Trang 1355-1362 - 1974
Folate distribution during higher plant development Abstract The total folate content of various tissues from pea seedlings was determined using a microbiological assay. In the seed the bulk of folate was located in cotyledons, but the embryo, representing only 2% of the total seed fresh weight, had a folate concentration about three times higher. In the presence of sulphanilamide, an inhibitor of folate biosynthesis, the initial folate content supported root elongation during the first 1–2 days. However, further growth of the seedling was not possible and required a de novo synthesis of folate. Following organogenesis, the folate content of young roots and shoots was similar to that in the initial embryo. In contrast, the folate content of young leaves increased rapidly to reach a value two to three times higher than in other tissues after 7 days of growth and remained roughly constant thereafter. The intracellular distribution of folate was estimated in 12‐day‐old leaves. Mitochondria, the site of folate synthesis, contained approximately 30% of the total cellular folate. The folate level in chloroplasts was about 100 times lower than in mitochondria, representing, on a protein basis, less than 4% of the total pool. We associate the bulk of folate with the cytosol plus nucleus (65–70% of the pool), although mitochondria (less than 5% of the cytoplasmic volume) had the highest concentration. Why there should be more folate in leaves, on a fresh weight basis, than in other tissues is not clear. The folate‐dependent enzymes involved in photorespiration (glycine decarboxylase and serine hydroxymethyltransferase) are located in mitochondria where they accumulate during greening. In contrast, the folate within mitochondria purified from either roots, etiolated leaves or green leaves was, on a protein basis, similar, suggesting that other factors related to light and photosynthesis might be involved. © 2001 Society of Chemical Industry
Tập 81 Số 9 - Trang 835-841 - 2001
The response of <i>Tenebroides mauritanicus</i> (L.) and <i>Tenebrio molitor</i> L. to methyl bromide at reduced pressures Abstract The response of larvae and adults of Tenebroides mauritanicus (L.) to methyl bromide at reduced pressures is complex. Four zones of differing susceptibility were found : (1) at 15–30 mm. Hg pressure high mortalities were due more to desiccation than the action of the fumigant; (2) at 30–50 mm. low mortalities coincided with loss of visible activity; (3) at 50–175 mm. increased activity and high mortalities occurred; (4) from 175 mm. to atmospheric pressure activity was normal and mortalities declined. In zones (2) to (4) the responses were independent of humidity. Larvae of Tenebrio molitor L. gave responses similar to those in zones (2), (3) and (4) but at different pressure ranges.
Tập 10 Số 7 - Trang 366-379 - 1959
Bioactivity of falcarinol and the influenceof processing and storage on its content in carrots (<i>Daucus carota</i> L) Abstract The concentration‐dependent activity of the polyacetylene falcarinol ((9Z )‐heptadeca‐1,9‐dien‐4,6‐diyn‐3‐ol), isolated from carrots, was investigated in a bioassay with primary mammary epithelial cells in collagen gels and compared with that of β‐carotene, the orange pigment in carrots. Falcarinol showed biphasic activity, having stimulatory effects between 0.01 and 0.05 µg ml−1 and inhibitory effects between 1 and 10 µg ml−1 , whereas β‐carotene showed no effect in the concentration range 0.001–100 µg ml−1 . The results are discussed in relation to the health‐promoting effects of carrots and related vegetables. Falcarinol was quantified in the carrot cultivars Bolero, Rodelika and Fancy by analytical reverse phase HPLC, subjected to various processing and storage conditions in order to study how long‐term storage, blanching, freezing and boiling influence the content of falcarinol. Long‐term storage of raw carrot cubes (1 cm3 ) reduced the falcarinol content by almost 35%. A similar reduction was found in steam‐blanched carrot cubes (1 cm3 ). Long‐term storage at −24 °C of steam blanched carrot cubes did not reduce the falcarinol content further. A reduction of almost 70% in the falcarinol content was found in carrot pieces boiled in water for 12 min compared with raw carrots. Copyright © 2003 Society of Chemical Industry
Tập 83 Số 10 - Trang 1010-1017 - 2003