Ferulic acid crosslinks in asparagus cell walls in relation to texture

Post-harvest toughening of asparagus spears is associated with a large increase in monomeric and diferulic acids in the cell walls of stem tissues. The purpose of this study has been to investigate the distribution of these phenolic components among cell wall polymers and the role they play in the formation of associated pectic-xylan-phenolic complexes in relation to post-harvest toughening. The phenolic esters are found in all the extractable polysaccharide fractions, particularly the 0.5 M KOH fraction, as well as the insoluble cellulose-rich residue. The storage-related increase occurs in all fractions but is most prominent in the 0.5 M KOH-soluble components. Degradation of 0.5 M KOH subfractions with pure polysaccharide degrading enzymes has confirmed the occurrence of pectic-xylan-phenolic complexes in which ferulic acid and its dehydrodimers are attached to the xylan component but not to the pectic component. Studies on cell separation show that the maturation- and storage-related increase in thermal stability of cell adhesion (and therefore texture) is probably due to an increase in phenolic cross linking of xylans mainly in the parenchyma tissues. This overcomes the thermal lability of the pectic polysaccharides that are responsible for cell adhesion in immature tissues. The storage-induced appearance of some of the diferulic acid moieties in a number of wall polymer fractions supports the hypothesis that the storage affect is a wound-induced response rather than a continuation of maturation-related activity.     

Identification of flavonoid diglycosides in several genotypes of asparagus from the Huétor-Tájar population variety

The qualitative and quantitative composition of flavonoids from the Huétor-Tájar population variety of asparagus (commonly known as " triguero") was investigated. Flavonoids were analyzed by reversed-phase high-performance liquid chromatography-diode array detection (HPLC-DAD). Liquid chromatography-mass spectrometry (LC-MS) under identical HPLC conditions was used to verify the identities of the flavonoid glycosides from triguero asparagus. The quantities of asparagus flavonoids were calculated according to concentration curves constructed with authentic standards. Total flavonoid contents, calculated as the sum of individual compounds, were determined and ranged from 400 to 700 mg/kg fresh weight. The most abundant was rutin, which represented 55-98% of the total flavonoid complement. Triguero asparagus were revealed to be an important source of not only quercetin derivatives but also kaempferol and isorhamnetin glycosides. Significant differences (p < 0.05) in the content and relative composition of flavonoids were found among the spears of the distinct asparagus genotypes from the Huétor-Tájar population variety.     

气象条件对西辽河平原绿芦笋产量和质量的影响

以2a生芦笋阿波罗为试材，在地处西辽河平原的内蒙古民族大学试验农场，研究了采笋期间气象条件对绿芦笋产量和质量的影响。结果表明，绿芦笋日合格笋产量、总产量均与近3日（采笋当日及前2日）积温间呈极显著正相关关系，当日温度对笋产量的影响最大，其次为前1日温度和前2日温度。采笋当日与前1日的日平均风速均与不合格笋的支数、产量呈极显著正相关关系，风力作用是形成弯曲笋和散头笋的主要原因之一。日最高、最低气温与不合格笋的支数、产量呈显著或极显著正相关关系，而温度日较差、空气湿度均与不合格笋支数和产量相关不显著。因此，西辽河平原种植芦笋在春季采笋期间设立风障、小拱棚等保护性设施是提高绿芦笋产量和质量的有效途径。     

Antioxidant activity of ethanolic extracts from several asparagus cultivars

Three different methods (antiradical activity, inhibition of primary oxidation, and ferric reducing power) have been used to evaluate the antioxidant activity of eight different asparagus cultivars and byproducts: white and green asparagus from Alcalá del Río (Guadalquivir Valley, Seville) and American hybrids, native spears, and their byproducts from Huétor-Tájar (Vega de Granada). The correlation between antioxidant activity and total phenol content was studied. Six standards were also tested to validate the modified methods for antioxidant activity determination. Results obtained for antiradical capacity and reducing power were very similar, and a high correlation with phenols was found (R > or = 0.9 for both tests). Sample origin was an important factor, spears from Huétor-Tájar having higher values (ARC between 7 and 10 and P(R) of 0.25-0.33) than those from Alcalá del Río (ARC 0.6-2 and P(R) of 0.05-0.07). Significant differences were found between spears with the same origin, suggesting that genetics are another factor to take into account. Asparagus inhibits lipid primary oxidation, but no correlation between the inhibition percentage and phenols was observed. Asparagus origin was the only factor that led to significant differences: samples from Huétor-Tájar had higher values (POIC between 18 and 32) than those from Alcalá del Río (POIC of 5-9). Byproducts from the canning industry at Huétor-Tájar were also assayed for antioxidant activity; the results obtained suggested that byproducts could be considered as an excellent source of natural antioxidants.     

Phenolic antioxidants richly contained in corn bran are slightly bioavailable in rats

Phenolic acids (PAs) have been shown to be beneficial to human health and are found most abundantly in corn bran ( approximately 4%, w/w), one of the main dietary fibers. This study therefore evaluated the bioavailabilities of phenolic antioxidants ferulic acid (FA) and p-coumaric acid (PCA) in refined corn bran (RCB) by determining their recovery in the plasma, urine, and feces of rats fed a single meal of a RCB diet containing 5% RCB or adapted to the RCB diet for 10 days. In both studies, 0.4-0.5% of ingested FA and 1.2-2.3% of ingested PCA were recovered in rat urine. By contrast, approximately 81% of FA and approximately 64% of PCA ingested with the single meal were excreted through the rat feces within 3 days after the ingestion. On the other hand, after rats were fed the RCB diet, total FA (all forms of FA) was recovered in plasma at a concentration of 35.0 +/- 2.0 microg/L, total FA and total PCA were excreted through urine at levels of 155.4 +/- 5.8 and 50.9 +/- 6.6 microg/day, respectively. These parameters showed no significant change (P = 0.93, 0.09, and 0.66, respectively) after rats were fed the RCB diet continuously for up to 10 days. These results suggest that the PAs in RCB are bioavailable in rats. Their bioavailabilities, however, are relatively low compared with their high content in RCB and not improved by the adaptation for 10 days to the enriched RCB diet. Additionally, comparison with the results of other studies revealed that high contents of FA and, especially, diferulic acids in cereal bran, which act as cross-links between bran cell wall polysaccharides, may not improve but, rather, limit the bioavailabilities of PAs in vivo.     

Thermal stability of texture in Chinese water chestnut may be dependent on 8,8'-diferulic acid (aryltetralyn form)

Ferulic acid (FA) cross-links have been implicated in the thermal stability of texture in Chinese water chestnut (CWC) tissues. The aim of the current study has been to investigate this concept further. CWC tissue strips were measured for their mechanical properties before and after extraction in increasing strengths of alkali. The mechanical properties were related to the associated mode of fracture (cell separation or breakage) at the fracture surfaces and the phenolic composition of the cell walls. CWC tissue softened after prolonged extraction in cold alkali due to an increase in the ease of cell separation. Analysis of wall-bound phenolics demonstrated that most FA moieties, including five of the six dehydrodimers, were released before tissue strength was reduced. Loss of strength was, however, coincident with the loss of 8,8'-diferulic acid, aryltetralin (AT) form. It has been suggested that this dehydrodimer may be particularly concentrated at the edge of the cell faces. These results provide further evidence for the involvement of this dehydrodimer in conferring thermal stability of cell-cell adhesion and hence texture in CWC. However, they do not exclude the other diferulates from involvement in cell adhesion.     

Comparing 1H‐NMR imaging and relaxation mapping of German white asparagus from five different cultivation sites

Nuclear magnetic resonance imaging (MRI) and complementary analytical techniques were used to address the question whether white asparagus (Asparagus officinalis L.) from different cultivation sites in Germany can be distinguished on the basis of NMR relaxation times. Five locations with contrasting soil properties and composition within the two asparagus‐cultivation regions Rhineland and Lower Franconia were selected for this project. For the first time, entire asparagus plants in their authentic soil environment excavated directly from the original harvest site were imaged by the NMR technique. However, they could not be employed for determination of relaxation times of spears in situ, because of artifacts arising from soil properties. Instead, market‐ready asparagus spears and freshly prepared spear saps from the five locations were used to acquire MRI data sets with different (slow and fast) imaging methods and to compute spatially resolved distributions (maps) of T₁, T₂, and T₂* relaxation times. Comparison of the data for pith, vascular tissue, and peel of the spears yielded only marginal, if any, differences in T₁, T₂, and T₂* between the specimens from the five locations, which were not sufficient for an unambiguous region‐related distinction. More pronounced differences in T₁, T₂, and T₂* were visible for the spear saps, allowing a clear distinction between individual specimens for each of the two cultivation regions. The results are discussed in terms of an application potential for correlated NMR relaxation times of tissue saps for future geographic authentication of agricultural produces.     

Phenolic Pattern of Bean (Phaseolus vulgaris L.) as an Indicator of Chronic Ozone Stress

From sowing till emergence of the fourth trifoliolate leaf, beans were exposed for seven hr a day to four ozone concentrations in open-top chambers: filtered air (FA), non-filtered air (NF), non-filtered air plus 30 ppb ozone (NF+) and non-filtered air plus 60 ppb ozone (NF++). Controls in ambient air of open plots (AA) were also available. The free polyphenolic pool of the first trifoliolate leaf was systematically investigated using HPLC. The groups of phenolics to which the three main chromatographic signals belonged were identified as hydroxycinnamic acid derivative for peak No 1 and flavonoids for peaks Nos 4 and 6. The metabolic regulation of phenolic accumulation could be recognized as different clusters based on specific phenolic patterns that reflected some of the tested atmospheric conditions. The comparison of AA and NF conditions revealed a ‘chamber effect’. FA and NF atmospheres gave rise to almost the same phenolic equilibriums dominated by a hydroxycinnamic acid derivative (about 53% of the total phenolics). Ozone addition was associated with a regular reduction of the percentage of peak No 1: about 40% for NF+ and 19% for NF++. Therefore, the significant decrease of the vacuolar storage of this phenolic compound (from 23 mg g^-1 dry weight for NF to about 3 mg g^-1 dry weight for NF++) can be regarded as a useful tool for monitoring long-term exposure to elevated ozone concentrations.     

Soluble and bound phenolic compounds in different Bolivian purple corn ( Zea mays L.) cultivars

In nine Bolivian purple corn ( Zea mays L.) varieties the content of phenolic compounds as well as the anthocyanin composition has been determined. The phenotypes under investigation included four red and five blue varieties (Kulli, Ayzuma, Paru, Tuimuru, Oke, Huaca Songo, Colorado, Huillcaparu, and Checchi). In purple corn, phenolic compounds were highly concentrated in cell walls. Thus, simultaneous determination of soluble and bound-form phenolics is essential for analysis, extraction, and quantification. The present study reports the determination of soluble and insoluble-bound fraction of phenolic compounds by HPLC-DAD and HPLC-ESI-MS(n) in Bolivian purple corn varieties. Enzymatic, thermal, and alkaline hydrolyses were used to obtain the cell wall-linked phenolic compounds. Ferulic acid values ranged from 132.9 to 298.4 mg/100 g, and p-coumaric acid contents varied between 251.8 and 607.5 mg/100 g dry weight (DW), respectively, and were identified as the main nonanthocyanin phenolics. The total content of phenolic compounds ranged from 311.0 to 817.6 mg gallic acid equivalents (GAE)/100 g DW, and the percentage contribution of bound to total phenolics varied from 62.1 to 86.6%. The total monomeric anthocyanin content ranged from 1.9 to 71.7 mg cyanidin-3-glucoside equivalents/100 g DW. Anthocyanin profiles are almost the same among the different samples. Differences are observed only in the relative percentage of each anthocyanin. Cyanidin-3-glucoside and its malonated derivative were detected as major anthocyanins. Several dimalonylated monoglucosides of cyanidin, peonidin, and pelargonidin were present as minor constituents.     

Health-promoting compounds in broccoli as influenced by refrigerated transport and retail sale period

Total aliphatic and indole glucosinolates, phenolic compounds (flavonoids and hydroxycinnamoyl derivatives), and vitamin C contents were evaluated in freshly harvested broccoli (Brassica oleracea L., var. italica, cv. Marathon) inflorescences. These were film-wrapped and stored for 7 days at 1 degrees C to simulate a maximum period of commercial transport and distribution. After cold storage, inflorescences were kept for 3 days at 15 degrees C to simulate a retail sale period. For wrapping, low-density polyethylene (LDPE) of 11 microm thickness was used. Gas composition was about 17% O(2) and 2% CO(2) during cold storage and about 16% O(2) and 3-4% CO(2) during shelf life within packages. The predominant glucosinolates were 4-methylsulfinylbutyl-glucosinolate (glucoraphanin), 3-indolylmethyl-glucosinolate (glucobrassicin), and 1-methoxy-3-indolylmethyl-glucosinolate (neoglucobrassicin). The predominant hydroxycinnamoyl derivatives were identified as 1,2,2'-trisinapoylgentiobiose, 1,2-diferuloylgentiobiose, 1,2'-disinapoyl-2-feruloylgentiobiose, and 3-O-caffeoyl-quinic (neochlorogenic acid). Results showed major losses at the end of both periods, in comparison with broccoli at harvest. Thus, the respective losses, at the end of cold storage and retail periods, were 71-80% of total glucosinolates, 62-59% of total flavonoids, 51-44% of sinapic acid derivatives, and 73-74% caffeoyl-quinic acid derivatives. Slight differences in all compound concentrations between storage and retail sale periods were detected. Distribution and retail periods had minimal effects on vitamin C. Weight loss was monitored at the end of both periods.     

Chemical composition of clarified bayberry (Myrica rubra Sieb. et Zucc.) juice sediment

Clarified bayberry juice turned hazy upon storage at 25 degrees C for 6 months, and the chemical composition of centrifugally separated sediment was analyzed. Bayberry juice haze was mainly protein-tannin haze. The lyophilized sediment contained 20.4 +/- 4.3% of protein, 70.2 +/- 2.6% of total polyphenols, 7.2% of monosaccharides, and 6.7 +/- 0.6% of ash. Amino acid analyses and molecular weight distribution estimation indicated that bayberry proteins were haze-active proteins with a molecular weight less than 8 kDa. Gallic acid, quercetin hexoside, quercetin deoxyhexoside, and quercetin were found in the methanol-dissolved sample, while gallic acid, protocatechuic acid, cyanidin, ellagic acid, and quercetin were detected in the acid-hydrolyzed sample. Ellagic acid was the dominant individual phenolic (9.9 +/- 0.19 g/100 g dry weight, 55.3% of the total amount) in the sediment. Monosaccharides of rhamnose, arabinose, mannose, glucose, and galactose in the sediment were most probably the glycoside moieties of the anthocyanins, flavonols, and elllagitannins. Metal ions of calcium, magnesium, potassium, iron, and copper also indicated the heterogeneous characteristics of the sediment.     

Domestic processing of onion bulbs (Allium cepa) and asparagus spears (Asparagus officinalis): effect on flavonol content and antioxidant status.

Two commonly consumed plant foods, onion bulbs and asparagus spears, were subjected to typical domestic processing, including chopping, maceration, and boiling. The impact of these processes on flavonol content was assessed. Further, the consequences of these processes on the antioxidant capacity of the tissues were evaluated with the beta-carotene bleaching method. Chopping significantly affected rutin content in asparagus, yielding an 18.5% decrease in 60 min; but in onions, quercetin 3,4'-diglucoside (Q(DG)) and quercetin 4'-glucoside (Q(MG)) were virtually unaffected by chopping. Boiling for 60 min had more severe effects, as it caused overall flavonol losses of 20.6 and 43.9% in onions and asparagus, respectively. Chopping of tissues did not considerably influence the antioxidant capacity, but boiling did provoke notable changes.     

Postharvest storage of white asparagus (Asparagus officinalis l.): changes in dietary fiber (Nonstarch polysaccharides).

Changes occurring in the content and composition of the dietary fiber of white asparagus during storage in different conditions were studied (2 degrees C; 2 degrees C in polyethylene bags with air; 2 degrees C in polyethylene bags with a selected gas mixture). The neutral sugars and uronic acid composition of dietary fiber was determined by gas chromatography and by a spectrophotometric method. The modifications observed in the dietary fiber of the asparagus stored at 2 degrees C were more rapid and pronounced than those in polyethylene bags. The most important changes corresponded to xylose and glucose from insoluble dietary fiber and galactose from soluble dietary fiber. Statistical analysis indicated that the modifications were significantly affected by the type of storage and time.     

Effect of genotype and storage time on stability of colour,phenolic compounds and ascorbic acid in red raspberry (Rubus idaeus L.) jams

Changes in colour, phenolic composition and ascorbic acid (AA) concentrations in jams made from eight, floricane fruiting, red raspberry genotypes stored for six months at 20°C were investigated. Additionally, the relationship between genotypes and quality parameters was assessed. On average for all genotypes, 83% AA degradation was observed during the first three months of storage. After six months, the concentrations of anthocyanins, total quercetin glycosides and lambertianin C decreased by 80%, 13% and 7%, while ellagic acid conjugates and total phenolics increased by 47% and 8%, respectively. The anthocyanins detected in highest concentrations in fresh jams, that is, cyanidin-3-(2^g-glucosylrutinoside), cyanidin-3-sophoroside, cyanidin-3-glucoside and cyanidin-3-rutinoside showed the highest stability during storage, that is, 28%, 21%, 12% and 11% left after six months of storage, respectively. A significant decrease in colour (lightness, chroma and hue) was also observed during storage. The colour changes of stored jams, however, were much slower than the pigment degradation. On average, lightness, chroma and hue decreased by 13%, 29% and 18% during six months of storage, respectively. The lowest anthocyanin degradation was observed in jams characterised by red-bluish colour and high initial anthocyanin content, that is, ‘Veten’, ‘RU024 01003’ and ‘RU974 07002’ with 72–78% degradation after storage for six months, while the highest losses (82–93%) were observed in jams characterised by saturated red-orange colour, high ellagitanin and low initial anthocyanin contents, that is, ‘Glen Magna’, ‘Malling Hestia’ and ‘Octavia’. The results indicate that the genotypes ‘RU024 01003’ and ‘RU974 07002’ might have the potential to replace ‘Veten’, the main cultivar for jam processing in Norway, as new cultivars for industrial processing provided good cultivation qualities and satisfactory taste and flavour of the products.     

Comparison of Swiss red wheat grain and fractions for their antioxidant properties

Swiss red wheat grain, bran, aleurone, and micronized aleurone were examined and compared for their free radical scavenging properties against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH*), radical cation ABTS*+ and peroxide radical anion O(2)*-, oxygen radical absorbance capacity (ORAC), chelating capacity, total phenolic content (TPC), and phenolic acid composition. The results showed that micronized aleurone, aleurone, bran, and grain may significantly differ in their antioxidant properties, TPC, and phenolic acid composition. Micronized aleurone had the greatest antioxidant activities, TPC, and concentrations of all identified phenolic acids, suggesting the potential of postharvesting treatment on antioxidant activities and availability of TPC and phenolic acids. Ferulic acid was the predominant phenolic acid in Swiss red wheat and accounted for approximately 57-77% of total phenolic acids on a weight basis. Ferulic acid concentration was well correlated with scavenging activities against radical cation and superoxide anion, TPC, and other phenolic acid concentrations, suggesting the potential use of ferulic acid as a marker of wheat antioxidants. In addition, 50% acetone and ethanol were compared for their effects on wheat ORAC values. The ORAC value of 50% acetone extracts was 3-20-fold greater than that of the ethanol extracts, indicating that 50% acetone may be a better solvent system for monitoring antioxidant properties of wheat. These data suggest the possibility to improve the antioxidant release from wheat-based food ingredients through postharvesting treatment or processing.     

Wheat gluten phenolic acids: occurrence and fate upon mixing

Ferulic acid (FA, 4.9-17.7 microg/100 mg), sinapic acid (SA, 1.4-3.5 microg/100 mg), and traces of p-coumaric acid and vanillic acid were detected after saponification of six wheat glutens from industrial and pilot-scale origins. FA and SA occurred mostly as soluble-bound and insoluble-bound forms according to their extractability by acetone/methanol/water (7:7:6, v/v/v). The major part of FA (50-95%) was found in the unextractable fraction, whereas SA was mostly extractable (64-85%). The carbohydrate contents of the glutens were determined also after acid hydrolysis. The highest levels of glucose, arabinoxylan, and FA were obtained from the unextractable fractions of the pilot-scale extracted glutens, probably in relation with a lower efficiency of washing during extraction compared to industrial processes. On the other hand, SA compounds were in similar concentrations in all samples, suggesting their involvement in specific interactions during gluten protein agglomeration. Saponification of the soluble-bound phenolic acids released mainly glucose, whereas a beta-glucosidase treatment had no effect. FA and SA extractability, especially that of soluble-bound ones, decreased strongly in overmixed gluten/water doughs. These low molecular weight conjugates of phenolic acids could be involved in the dough breakdown phenomenon.     

Ellagic acid, vitamin C, and total phenolic contents and radical scavenging capacity affected by freezing and frozen storage in raspberry fruit

The ellagic acid, total phenolic, and vitamin C contents in four raspberry cultivars (Heritage, Autumn Bliss, Rubi, and Zeva) grown in Spain were detected and quantified by HPLC in fresh, just frozen, and stored fruits at -20 degrees C for a one year period. Ellagic acid [207-244 mg kg(-)(1) of fresh weight (fw)], total phenolic (137-1776 mg kg(-)(1) of fw), and vitamin C (221-312 mg kg(-)(1) of fw) contents in raw material were higher in the late cultivars Zeva and Rubi than in the early cultivars Autumn Bliss and Heritage. The freezing process slightly affected the values of extracted ellagic acid, total phenolic, and vitamin C content. At the end of long-term frozen storage (12 months), no significant change of total phenolic content extracted was observed, but significant decreases of 14-21% in ellagic acid and of 33-55% in vitamin C were quantified. Free radical scavenging capacity measured as antiradical efficiency (AE) depends on the seasonal period of harvest. Late cultivars, Rubi (6.1 x 10(-)(4)) and Zeva (10.17 x 10(-)(4)), showed higher AE than early cultivars, Heritage (4.02 x 10(-)(4)) and Autumn Bliss (4.36 x 10(-)(4)). The freezing process produced a decrease of AE values in the four cultivars ranging between 4 and 26%. During the frozen storage, the AE values reached after the freezing process remained unchanged.     

Annual evolution of fatty acid profile from muscle lipids of the common carp (Cyprinus carpio) in Madagascar inland waters

Annual evolution of muscle lipids fatty acid (FA) from common carp (Cyprinus carpio) has been determined in 2001 through monthly samplings in the reserve pond of Sisaony (SIS series) and Itasy Lake (ITA series) of the Madagascar highlands. Total lipids from muscle were extracted and quantified according to the Bligh and Dyer method. FA identification was performed by GC-MS of FA methyl esters and FA pyrrolidides and led to the identification of 41 FA; routine analyses of FA were made by capillary GC. Principal component analysis (PCA) was performed on the data set to compare FA profiles. Lipid content is low, ranging from 0.91 to 1.73% of wet muscle, with a low stage during the hot season (January-April) and a higher stage during the cold season (July-October). Three FA dominated the FA composition: oleic acid (17.0-21.5%), palmitic acid (13.1-16.1%), and linoleic acid (9.6-13.2%). Polyunsaturated fatty acids (PUFA) were present in appreciable amounts: arachidonic acid (AA; 2.9-5.9%), docosahexaenoic acid (DHA; 2.9-6.7%), eicosapentaenoic acid (EPA; 1.9-3.4%), and docosapentaenoic acid (DPA; 1.9-4.3%). Two opposite evolution schemes appear within two groups of FA; on the one hand PUFA (both n-3 and n-6 series) show a maximum in August-October and a minimum in January-April, and, on the other hand, oleic, palmitic, and linoleic acids show the opposite maxima and minima. PCA results give confirmation of these evolution schemes, the two groups of FA giving opposite high factor loadings on axis 1. The SIS and ITA series are differentiated by axis 2 by mean of minor FA, mostly odd- and branched-chain. Results indicate that common carp, the second most abundant freshwater fish in Madagascar highlands waters, may be an interesting source of dietary PUFA.     

Analysis of fumonisin B(1) in Fusarium proliferatum-infected asparagus spears and garlic bulbs from Germany by liquid chromatography-electrospray ionization mass spectrometry

Fusarium proliferatum is one of a group of fungal species that produce fumonisins and is considered to be a pathogen of many economically important plants. The occurrence of fumonisin B(1) (FB(1)) in F. proliferatum-infected asparagus spears from Germany was investigated using a liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB(1)-d(6) as internal standard. FB(1) was detected in 9 of the 10 samples in amounts ranging from 36.4 to 4513.7 ng/g (based on dry weight). Furthermore, the capability of producing FB(1) by the fungus in garlic bulbs was investigated. Therefore, garlic was cultured in F. proliferatum-contaminated soil, and the bulbs were screened for infection with F. proliferatum and for the occurrence of fumonisins by LC-MS. F. proliferatum was detectable in the garlic tissue, and all samples contained FB(1) (26.0-94.6 ng/g). This is the first report of the natural occurrence of FB(1) in German asparagus spears, and these findings suggest a potential for natural contamination of garlic bulbs with fumonisins.     

On the Compositional Analysis of Fatty Acids in Pork

Fatty acid (FA) composition of pork is an important issue for the pig industry and consumers. Fatty acid composition is commonly described as the percentages of a set of FA relative to total FA and therefore should be statistically treated as compositional data. To our knowledge there is no reference in the literature where specific methods for compositional data analysis have been applied to analyze FA composition in meat quality research. The purposes of this study were (1) to present an overview of compositional data analysis techniques, (2) to apply them to the analysis of the FA composition of muscles and subcutaneous fat from 941 pigs as a case study, and (3) to discuss and interpret the results with respect to those obtained using standard techniques. Results from both approaches indicate that FA composition differed across tissues and muscles but also, for a given muscle, with the intramuscular fat content. It is concluded that FA composition in pork did not display enough variability to become critical for standard statistics, particularly if the individual FA parts remain the same across experiments. However, even in such case, compositional analysis may be useful to correctly interpret the correlation structure among FA.