A novel real-time polymerase chain reaction method for the detection of macadamia nuts in food

A real-time PCR-based method for the detection of macadamia nuts (fruits of Macadamia integrifolia or M. tetraphylla or their hybrids) in food products is described. The method consists of DNA isolation by chaotropic solid phase extraction and subsequent PCR with macadamia-specific primers and a TaqMan fluorescent probe. The primers and the probe were targeted to the gene encoding for vicilin precursor. The method was positive for M. integrifolia and M. tetraphylla and negative for 16 other plant species used in food industry, including peanuts, walnuts, hazelnuts, almonds, pistachio nuts, cashew nuts, Brazil nuts, and chestnuts. The DNA-based detection limit of the method was 1.45 pg. Using a series of model samples with defined macadamia nut contents, a practical detection limit of 0.02% (w/w) macadamia nuts was determined. Practical applicability of the PCR method was tested by the analysis of 14 confectionery samples. For all of the samples, results conforming to the labeling were obtained. The presented PCR method is useful for relatively fast, highly selective, and moderately sensitive detection of macadamia nuts in food samples.     

Moisture characteristics of macadamia nuts in relation to storage

The moisture content/relative humidity characteristics of nuts from two species of Macadamia have been examined. For Macadamia tetraphylla the whole nut moisture content corresponding to a relative humidity (r.h.) of 70%, accepted as the maximum for safe storage, was 11.8%. The moisture content can be determined with an electrical moisture meter by calibrating against standard laboratory procedures. The sorption isotherm of M, integrifolia appeared somewhat different.     

Lipid quality and filleting yield of reared meagre (Argyrosomus regius)

Reared meagre (Argyrosomus regius) of average weight 1278 g was evaluated for its filleting yield and fillet lipid quality. Filleting yield averaged 42.2%, while very low levels of muscle fat deposits were measured (1.06%). Analysis of lipid classes revealed a high proportion of polar lipids (48.3–59.1%) and low levels of neutral fatty acids (40.9–51.7%) when compared to corresponding values of other farmed fish species. Phosphatidyl‐choline (PC) was the dominant polar lipid (2.92 mg g^?1 muscle), while cholesterol the most abundant neutral lipid (1.68 mg g^?1 muscle). The fatty acid composition of meagre fillet generally reflects the dietary fatty acids. Among n‐3 fatty acids, eicosapentaenoic (4.58%) and docohexaenoic (15.0%) were measured to be the most abundant ones, and 18:2n‐6 (11.9%) was the most common n‐6 fatty acid. The fatty acid profiles of polar and neutral fractions differ, with monounsaturated fatty acids being predominant in the neutral and n‐3 polyunsaturates in the polar lipids. The high polar lipid contents and n‐3 fatty acids and the low atherogenic and thrombogenic indexes indicate a high quality of this species’ lipids.     

Comparative study of fatty acid composition,vitamin E and carotenoid contents of palm oils from four varieties of oil palm from Côte d'Ivoire

BACKGROUND: Fatty acid, tocopherol, tocotrienol and carotene contents were assessed in four oil palm species from the National Centre of Agronomical Research of Côte d'Ivoire, two of which were the basal Lamé (HP1) and Deli (HP2) collections and two of which resulted from crossings between HP1 and HP2 varieties of Eleais guineensis, HP3 and HP4 being identified as the first and second cycle selection, respectively. RESULTS: Palm oil species were characterized by the richness in polyunsaturated fatty acids composition (48–60%) compared to saturated fatty acids (40–52%), especially the first variety, which was from the base collection, and the two hybrids ensuing from crossing. Total carotene content of those varieties was higher and accounted for 832–3575 µg g^?1, and the β‐carotene level (580–2390 µg g^?1) was predominant. Total vitamin E content was 864–1124 µg g^?1, with a notable higher content of tocotrienols, especially γ‐and α‐tocotrienol, ranging from 400 to 515 µg g^?1 and from 238 to 350 µg g^?1, respectively. CONCLUSION: Crossing seemed to be useful in improving the performance and analytical characteristics of the base collection materials. Copyright © 2009 Society of Chemical Industry     

Optimal salting of macadamia (Macadamia integrifolia) nuts

Roasted macadamia (Macadamia integrifolia Storey) nuts were salted at various levels up to 19 g kg^?1 and presented to a taste panel. The results showed that the assessors could be divided into 'salt dislikers', to whom perceived quality decreased linearly with increase in salt content, and 'salt likers', to whom perceived quality increased as the salt content increased. It follows that the nuts can be produced to suit these two market segments separately, or else a single lightly salted compromise product can be offered to both groups.     

Food chain approach to lowering the saturated fat of milk and dairy products

Lactating cow diets were supplemented with high‐oleic acid sunflower oil over two production periods spanning two years, to modify the milk fat, partially replacing saturated fatty acids with cis‐monounsaturated fatty acids. The resulting milk was used for ultrahigh‐temperature milk, butter and Cheddar cheese production, and fatty acid profiles were compared with those of conventionally produced products. Fat from products made with modified milk had lower saturated fatty acids and higher cis‐ and trans‐monounsaturated fatty acid concentrations than that of conventional products. This was consistent over both production periods, demonstrating that this food chain approach could be adopted on a wider scale.     

Influence of a severe reduction of the feeding level during the period immediately prior to free‐range fattening on performance and fat quality in Iberian pigs

BACKGROUND: Restricted feeding before fattening is a common procedure in the production of Iberian pigs, but little scientific information about its consequences on productive traits and characteristics of fat is available. This work studied the effect of a severe feeding restriction previous to the free‐range fattening on carcass and fat quality traits in Iberian pigs, considering two different feeding levels (high restriction: HR; versus maintenance level: M) before free‐range fattening. RESULTS: Animals from the M group showed longer and higher‐perimeter hams and tended (P < 0.10) to show higher slaughter and carcass weights, carcass inner length and loin and sirloin weights than HR ones. Animals from the HR group showed lower proportions of total saturated fatty acids (SFA) and higher total monounsaturated fatty acids in the backfat inner layer than those from the M group. Total polyunsaturated fatty acids in intramuscular neutral lipids were higher in HR pigs than in M ones, while stearic acid (C18:0) was lower. The average daily gain, fatty acid profile of the outer backfat layer and that of the hepatic polar and neutral lipids and the rheological features of backfat inner layer remained unaffected. CONCLUSION: A severe reduction of the feeding level previous to free‐range fattening does not produce compensatory growth, tends to diminish carcass quality and to slightly increase IMF content and improves the fatty acid profile of the inner backfat layer. Copyright © 2007 Society of Chemical Industry     

Fatty acids distribution in different tissues of wild and reared Seriola dumerili

In this study, we compared the lipid and fatty acids content, between cultured and wild Seriola dumerili, in different edible portions. Results showed that cultured fish contained a higher level of lipids than wild fish. The fatty acids profiles revealed that, among all the split‐fish side, palmitic (C16:0) and oleic (C18:1n‐9) acid were the principal saturated and monounsaturated fatty acids, in cultured and wild S. dumerili. On the other hand, wild S. dumerili contained a higher level of saturated (38.12 ± 0.54% vs. 33.66 ± 0.15% in cultured fish), monounsaturated (33.13 ± 1.07% vs. 26.49 ± 0.17%), n‐3 polyunsaturated fatty acids (PUFA) (23.90 ± 1.02% vs. 19.77 ± 0.51%) particularly docosahexaenoic acid (DHA) (18.83 ± 0.48% vs. 11.77 ± 0.42%). However, the cultured fish showed a higher level of n‐6 PUFA due principally to the higher value of linoleic acid (C18:2n‐6). In fact, changes in fatty acids content between anatomical areas marked differences in the muscle quality of wild and cultured S. dumerili. According to this study, both groups of wild and farmed S. dumerili have nutritional benefits for human health. Cultured fish were characterised by higher hypocholesterolaemic and hypercholesterolaemic fatty acids ratio for all samples studied and a lower n‐3/n‐6 ratio due to the abundance of n‐3 PUFA particularly DHA in wild fish.     

Distribution of fatty acids in triacylglycerols and phospholipids from peas (Pisum sativum L.)

BACKGROUND: The fatty acid distribution of triacylglycerols (TAG) and major phospholipids (PL) obtained from four varieties of peas (Pisum sativum) was investigated. The total lipids extracted from the peas were separated by thin layer chromatography into seven fractions. RESULTS: The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while hydrocarbons, steryl esters, free fatty acids and diacylglycerols (sn‐1,3 and sn‐1,2) were also present in minor proportions (5.6–9.2%). The main PL components isolated from the four varieties were phosphatidylcholine (42.3–49.2%), phosphatidylinositol (23.3–25.2%) and phosphatidylethanolamine (17.7–20.5%). Significant differences (P < 0.05) in fatty acid distribution were found for different pea varieties. Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. However, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident among the four varieties: unsaturated fatty acids were predominantly located in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in the oils of the peas. CONCLUSION: These results should be useful to both producers and consumers for the manufacture of pea foods in Japan. Copyright © 2007 Society of Chemical Industry     

Assessment and profiling of the fatty acids in two ackee fruit (Blighia sapida Köenig) varieties during different ripening stages

BACKGROUND: The ripening of fruits is characterized by physical, chemical and biochemical compositional changes such as color, sugars and phenolic compounds. Ackee fruit is famous in Jamaica and the Caribbean. This study aimed to assess the variation of fatty acids in two varieties (cheese and butter) ackee (Blighia sapida) fruits during five different ripening stages. RESULTS: The total fatty acid content of ackee fruit was much higher in arils and ranged from 283.4 to 465.1 g kg^?1 dry weight (DW), while in husk they ranged from 235.2 to 465.1 g kg^?1 DW in both varieties. Total fatty acid content declined in the arils and the husks as the fruit ripened. Five major fatty acids were found: palmitic acid (C16:0) and stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). In the arils, oleic acid was found at the highest concentration, followed by palmitic, stearic, linoleic and last linolenic acid. The unsaturated:saturated ratio of fatty acids varied from 1.23 to 3.26 in the arils of both varieties, and from 1.03 to 5.05 in the husk. Monounsaturated:polyunsaturated fatty acids ranged from 8.56 to 25.19 in the arils and from 0.62 to 2.33 in the husk. CONCLUSION: The results show that ackee arils contain much higher levels of fats than the husk and the major fatty acid in the arils was oleic acid (Δ9‐cis‐oleic acid, an omega n‐9), while in the husk unsaturated fatty acids were higher than the saturated ones. Oleic acid was the major fatty acid in both varieties, and aril fatty acid content was 10–20 times higher than in the husk. In both varieties, unsaturated fatty acids were relatively higher than saturated ones; however, total fatty acids showed a decline with ripening for arils and husk tissues. © 2012 Society of Chemical Industry     

Fatty acids and all‐trans‐β‐carotene are correlated in differently colored rice landraces

A set of 54 rice landrace samples was compiled from various Asian countries, including six red/brownish and eight black/purple varieties. Brown rice samples were analyzed for lipid content and fatty acid profile, as well as all‐trans‐β‐carotene content. Black/purple varieties were found to be higher in crude lipid content than the red/brownish and colorless varieties. They also had a higher β‐carotene content than the other two color classes. The highest β‐carotene content determined was 0.22 mg kg⁻¹. Black/purple varieties tended to have a higher proportion of saturated fatty acids in their lipid fraction and a lower proportion of unsaturated fatty acids. The differences were statistically significant (P < 0.05) for oleic acid, which accounted for 42.1% of the lipid fraction in black/purple varieties and for 45.3% and 46.3% in red/brownish and colorless varieties, respectively. β‐Carotene content showed a significantly positive correlation with the crude lipid content (P < 0.001) and the content of saturated fatty acids (P < 0.001) on a dry matter basis. However, it was not correlated with the unsaturated fatty acids content on a dry matter basis. Within the total lipid extract, β‐carotene showed a significantly positive correlation with the proportion of saturated fatty acids (P < 0.01), especially palmitic acid (P < 0.01), and a significantly negative correlation with unsaturated fatty acids (P < 0.001), especially oleic acid (P < 0.01). Copyright © 2005 Society of Chemical Industry     

Camelina sativa cake improved unsaturated fatty acids in ewe's milk

BACKGROUND: Camelina sativa cake (CSC), a rich source of unsaturated fatty acids, in the case of ruminants, may improve the energy value of a diet and also increase the unsaturated fatty acid content in milk. Effects of basal diet (control), basal diet plus 30 g kg⁻¹ of CSC in dietary dry matter (DM), basal diet plus 60 g kg⁻¹ of CSC in dietary dry matter on milk production and the fatty acid composition of ewe's milk with particular emphasis on the monoenes and conjugated isomers of linoleic acid content were examined. RESULTS: Elevated concentration of total monounsaturated fatty acids, the effect of an increase in monounsaturated fatty acids in the trans configuration, as well as the increased content of total polyunsaturated fatty acids, resulted from CSC supplementation. Total saturated fatty acid concentration was decreased. CONCLUSION: Milk from CSC‐supplemented ewes was characterized by increased levels of beneficial nutritional factors, including mono‐ and n‐3 polyunsaturated fatty acids, and was also by lower atherogenic and thrombogenic indices. Taking into consideration all the obtained results and recommended fat concentrations in a daily ruminant ration, we recommend supplementing a dairy ewe's diet with 30 g kg⁻¹ DM of CSC cake in practice. Copyright © 2011 Society of Chemical Industry     

Growth,carcass traits,chemical composition and fatty acid profile in beef from Charolais and Simmental bulls fed different types of dietary lipids

BACKGROUND: The effect of breed and whole sunflower seed on performance, carcass traits and the composition of meat was evaluated in Charolais (CH) and Simmental (SI) bulls. Samples of musculus longissimus lumborum (MLL) and musculus infraspinatus (MIS) were analysed. RESULTS: The CH bulls had a lower feed intake per kg of gain, a higher killing‐out percentage and produced more valuable carcasses. The muscles from SI bulls contained more monounsaturated fatty acids (FA) and less saturated FA (in g kg^?1 FA) than the muscles from CH bulls. The sunflower seed supplement increased the proportions of linoleic acid and c9t11 conjugated linoleic acid and the ratio of polyunsaturated fatty acids (PUFA) to saturated FA and decreased the index of atherogenicity of FA in meat lipids. CONCLUSION: The results of this study demonstrated the superiority of the CH over the SI breed in a number of economically important traits. The breed effect on the nutritional quality of meat was ambiguous. Meat lipids of the SI bulls contained more unsaturated FA but also more PUFA n‐6 and a higher PUFA n‐6/PUFA n‐3 ratio. Copyright © 2008 Society of Chemical Industry     

Influence of environmental temperature on composition of lipids in edible flesh of rainbow trout (Oncorhynchus mykiss)

The adaptative changes in the fatty acid composition of the main lipid classes in rainbow trout (Oncorhynchus mykiss) edible flesh in response to environmental variation in water temperature were investigated. The research was carried out on intensively farmed trout sampled at different times of the year. Neutral lipids (NL), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were separated using flash chromatography. Compared with summer acclimatisation, a decrease in neutral lipids of about 19% was observed in winter, accompanied by increases in phosphatidylethanolamine and phosphatidylcholine of about 41 and 29%, respectively. The metabolic adjustment in cold adaptation caused an increase in the levels of unsaturated fatty acids and monoenes of the oleic acid ω9 family and an increase in the levels of unsaturated fatty acids of the linoleic acid ω3 family. At the same time a reduction in the levels of saturated and monounsaturated fatty acids of the oleic acid ω9 family was observed. This pattern turned out to be particularly evident in phosphatidylcholine. The net result of these changes in composition was a significant increase in the polyunsaturated/saturated and polyunsaturated/monoenic fatty acid ratios in the edible flesh. Copyright © 2003 Society of Chemical Industry     

The fatty acid composition of the lipids from two species of hake

The fatty acid composition of lipids extracted from the livers, muscle and skin of two hake species Merluccius capensis and M. paradoxus were studied. In one instance a comparison was made between the fatty acid composition of the phospholipid and triglyceride fractions of the lipids. In pre-spawning fish there appears to be a tendency for M. capensis to have fat of higher unsaturation than M. paradoxus. The only consistent species difference found was the high level of unsaturation of skin lipids relative to muscle lipids in M. paradoxus, a species living at greater depth and lower water temperatures. The major saturated fatty acid in hake lipids is that with 16 carbon atoms, the major monoenoic acid the one with 18 carbon atoms, while C_22:6 is the dominant polyenoic fatty acid and C_20:5 the second most plentiful in hake lipids. Phospholipids form a small proportion of the lipid from dark muscle. They are particularly rich in the fatty acids C_16:0 and C_22:6.     

Fatty acids and triacylglycerols in the seed oils of Saudi Arabian date (Phoenix dactylifera L.) palms

Total lipids, fatty acids and triacylglycerols in seeds of the four Saudi Arabian date cultivars ‘Anbra’, ‘Megadwel’, ‘Sacai’ and ‘Sfwai’ were analysed. Total lipid contents ranged between 7.3 and 8.6%. Oleic, lauric and myristic acid represented the most abundant fatty acids in date seed oil. HPLC-DAD-ESI-MSⁿ analysis enabled the identification of 40 triacylglycerols with equivalent carbon number (ECN) 36–54, of which 17 were detected for the first time. Triacylglycerols mainly comprised LaOL, LaLaL, LaML, MML/LaPL and LaOO. ‘Anbra’ oil was characterised by highest proportions of saturated fatty acids and triacylglycerols with ECN 36 and 48–54. Unsaturated fatty acids prevailed in the three remaining varieties. Elevated proportions of triacylglycerols with medium ECNs were found in ‘Megadwel’ and ‘Sfwai’ oils. Aside from highest total lipid contents, ‘Sacai’ seeds predominantly contained triacylglycerols with low ECNs. Multivariate statistical analyses elucidated varietal influences on the fatty acid and triacylglycerol composition of date seed oil.     

Changes in Fatty Acids and Sensory Quality of Fresh Water Prawn (Macrobrachium rosenbergii) Stored Under Frozen Conditions

The effects of frozen storage and packaging methods on the oxidation of fatty acids and rancidity development in fresh-water prawn Macrobrachium rosenbergii were studied. The lipids of these fresh prawns contained 23% saturated, 46% monounsaturated, and 31% polyunsaturated fatty acids. The fatty acids, especially the unsaturated ones decreased during frozen storage for 6 months at -18°C, regardless of the packaging procedure employed. No objectionable rancid flavor was detected in these prawns during the 6-month frozen storage study.     

GC/MS分析俄罗斯鲟鱼不同部位脂肪酸组成

通过Folch法提取俄罗斯鲟鱼不同部位总脂,采用GC/MS法对其脂肪酸组成进行分析。通过质谱数据库检索和标准品对照鉴定脂肪酸组成。研究表明,鱼肉、鱼卵、鱼皮、鱼腹中脂肪酸种类及含量类似,多不饱和脂肪酸含量均大于40%,其次为单不饱和脂肪酸(30%左右)和饱和脂肪酸(17%左右),多不饱和脂肪酸以9,12-十八碳二烯酸和DHA为主。鱼肉中总脂含量12.83%,其中,多不饱和脂肪酸为42.37%,EPA+DHA为17.25%;鱼卵总脂含量为14.46%,其中n-3脂肪酸为22.10%;鱼皮含有较高含量的n-6脂肪酸(19.43%);鱼腹总脂含量14.45%,含有较高含量的多不饱和脂肪酸(42.66%)和单不饱和脂肪酸(34.07%),EPA+DHA为17.38%;鱼鳔中未检测到n-3和n-6脂肪酸;鱼肝总脂含量为55.92%,单不饱和脂肪酸含量尤为突出,高达55.81%,以9-十八碳烯酸(49.82%)为主,饱和脂肪酸含量仅为17.24%;椎骨中总脂仅为0.09%。     

Fatty acid composition of seed oil of different Sorghum bicolor varieties

In order to find out new sources of premium quality edible oil in the country, seeds of ten varieties of Sorghum bicolor were initially analyzed for their total oil contents. The seed oil was later fractionated into eight fatty acids including two new saturated fatty acids. The oil contents were determined by Soxhlet method and compared with the results obtained by NMR analysis. The total oil contents in the seeds of sorghum ranged from 5.0 to 8.2 % (w/w), indicating non significant difference obtained by two different techniques. The results revealed that oleic acid (31.12–48.99%), Palmitoleic acid (0.43–0.56%), linoleic acids (27.59–50.73%), linolenic acid (1.71–3.89%), stearic acid (1.09–2.59%) and palmitic acid (11.73–20.18%) was present in the seed oil of different sorghum varieties when analyzed by GC–MS. It was observed that in most of the varieties polyunsaturated fatty acids (PUFA) were higher than monounsaturated fatty acids (MUFA). The two atypical SFAs, octanedioic (C8:0) and azelaic acid (C9:0) were found in some varieties. These results suggest that these S. bicolor varieties could be additional sources of edible oil due to presence of clinically important saturated and high concentration of unsaturated fatty acids. A large scale production of the seed oil after refining process can contribute towards alleviation of edible oil shortage in the country with increased use of premium quality oil.     

Effects of oil roasting temperature and time on the quality of two Macadamia integrifolia cultivars

The effects of oil roasting temperature and time on the quality of kernels from two Macadamia integrifolia cultivars, were determined. A high quality product was obtained by roasting at 115°C for 19–35 min, 125°C for 10–14 min or 135°C for 4 min. There was a significant deterioration in the quality of nuts from all roasting treatments when stored for 6 months at ambient temperature in lacquered cans at a pressure of ?85 kPa. Further deterioration had occurred after 12 months storage.