Effects of dietary forage-to-concentrate ratio and forage type on milk phospholipids and fatty acid composition of polar lipids.

The effects of grass silage and red clover silage on milk fatty acid (FA) composition are extensively studied, but little is known of their effects on minor lipid constituents of milk fat globule membrane. We investigated the effects of forage:concentrate (FC) ratio in grass silage-based diets and forage type (grass silage vs. red clover silage) on selected molecular species of milk phospholipids (PL) and the FA composition of PL. Ten multiparous Nordic Red cows were offered following dietary treatments: grass silage-based diets containing 70:30 (HG) or 30:70 (LG) FC ratio or a red clover silage-based diet (RC) comprising 50:50 FC ratio on a dry matter basis. The most abundant molecular species within the phosphatidylcholines was 16:0-18:1 phosphatidylcholine that was increased by 18% in HG compared with LG milk. Dietary treatments did not affect the relative proportion of 18:1-18:1+18:0-18:2 phosphatidylethanolamine that was the most prevalent species (ca. 44%-45%) in that class. We identified the d18:1-22:0 sphingomyelin as the most abundant sphingomyelin species that tended to increase in HG milk compared with LG. The FC ratio did not affect the relative proportions of saturated FA nor monounsaturated FA in PL, but the proportion of cis-9 18:1 was elevated in HG versus LG milk, whereas the proportion of 18:2n-6 was 50% higher in LG versus HG milk. The RC diet increased monounsaturated FA and 18:3n-3 levels in PL compared with grass silage-based diets and decreased the relative proportion of saturated FA. However, the RC diet did not affect the relative proportion of polyunsaturated FA in PL, although red clover silage typically increases the proportion of polyunsaturated FA in milk fat. This study provides valuable knowledge of the minor lipid components in milk on species level in relation to common feeding strategies in high-forage systems.

APOE Genotype Disclosure and Lifestyle Advice in a Randomized Intervention Study with Finnish Participants.

BACKGROUND: The APOE ε4 allele is associated with higher risks of cardiovascular diseases and Alzheimer disease than ε3 and ε2. OBJECTIVES: We studied the effectiveness of dietary and lifestyle guidance and personal genetic risk information [ε4 carrier (ε4+); ε4 noncarrier (ε4-)] as motivators for a healthier lifestyle. METHODS: A total of 188 healthy Finnish volunteers (82.4% women; mean ± SD age: 51.0 ± 5.6 y; BMI: 26.0 ± 3.6 kg/m2; total cholesterol: 5.2 ± 0.9 mmol/L) participated in our randomized intervention study. The participants were genotyped for APOE and divided into intervention (INT; INTε4+, n = 33; INTε4-, n = 57) and control groups (CTRL; CTRLε4+, n = 36; CTRLε4-, n = 62). Blood samples, measured observations, and questionnaire data were obtained at baseline and at 1 and 1.5 y. INT participants received their ε4 carrier status at baseline. Monthly Internet-based guidance based on the Finnish Dietary guidelines was provided for all. RESULTS: The proportion of SFAs in plasma over time fluctuated less in INTε4+ than in the other groups (P-interaction < 0.05; primary outcome). The lifestyle guidance increased vegetable consumption from 3.5 to 3.6 portions/d, improved the dietary fat quality score by 5.3%, increased the plasma n-3 (ω-3) FA proportion by 7.3%, and decreased the consumption of high-fat/high-sugar foods from 7.3 to 6.5 portions/wk and total- and LDL-cholesterol concentrations by 4.3% and 6.1%, respectively, in the entire participant population (P < 0.05; secondary outcome). Compared with the ε4- participants, ε4+ participants had 2.4% higher plasma n-6 (ω-6) FA, lower C-peptide (3.9 compared with 4.2 nmol/L × h) and sensitive C-reactive protein values, and decreased plasma malondialdehyde concentrations over time (P < 0.05; secondary outcome). CONCLUSIONS: Lifestyle guidance given to healthy Finnish participants yielded small but beneficial changes. The INTε4+ group did not seem markedly more responsive to the guidance than the other groups.This trial was registered at clinicaltrials.gov as NCT03794141.

The effect of dietary forage to concentrate ratio and forage type on milk fatty acid composition and milk fat globule size of lactating cows.

We examined the effects of 2 grass silage-based diets differing in forage:concentrate (FC) ratio and those of a red clover silage-based diet on intake, milk production, ruminal fatty acid (FA) biohydrogenation, milk FA composition, and milk fat globule (MFG) size distribution. Ten multiparous Nordic Red cows received the following treatments: grass silage-based diets containing high (70:30, HG) or low (30:70, LG) FC ratio or a red clover silage-based diet with an FC ratio of 50:50 (RC) on a dry matter basis. Determinations of MFG were performed from fresh milk samples without addition of EDTA so the results of fat globules >1 µm in diameter are emphasized instead of the entire globule population. Lower FC ratio in grass silage-based diets increased milk production with no effect on daily fat yield, leading to 13% lower milk fat concentration. The effect of FC ratio on MFG size was moderate. It did not affect the volume-weighted diameter in grass silage-based diets, although LG lowered the volume-surface diameter of MFG in the size class >1 µm compared with HG. Compared with HG, feeding LG moderately decreased the biohydrogenation of 18:2n-6, leading to a higher level of polyunsaturated fatty acids in milk fat. Feeding RC lowered milk fat concentration and daily milk fat yield compared with grass silage-based diets. The volume-weighted diameter of MFG in the size class >1 µm was smaller in RC milk compared with grass silage-based diets. Feeding RC increased the flow of 18:3n-3 at the omasum by 2.4-fold and decreased the apparent ruminal 18:3n-3 biohydrogenation compared with grass silage-based diets despite similar intake of 18:3n-3. It also resulted in the lowest amount of saturated FA and the highest amounts of cis-9 18:1, 18:3n-3, and polyunsaturated FA in milk. In conclusion, LG decreased milk fat content and induced minor changes in MFG size distribution compared with HG, whereas RC lowered milk fat production, altered milk FA composition to nutritionally more beneficial direction, and led to smaller MFG compared with grass silage-based diets.

Quantification of triacylglycerol regioisomers by ultra-high-performance liquid chromatography and ammonia negative ion atmospheric pressure chemical ionization tandem mass spectrometry.

The regioisomer composition of triacylglycerols (TAGs) in various vegetable oils was determined with a new liquid chromatography/tandem mass spectrometry (LC/MS/MS method). A direct inlet ammonia negative ion chemical ionization (NICI) MS/MS method was improved by adapting it to LC negative ion (NI) atmospheric pressure chemical ionization (APCI) MS/MS system using ammonia as nebulizer gas. The method is based on the preferential formation of [M-H-RCOOH-100](-) ions during collision-induced dissociation by loss of sn-1/3 fatty acids from [M-H](-) ions. Calibration curves were created from nine reference TAGs: Ala/L/L, Gla/L/L, L/L/O, L/O/O, P/O/O, P/P/O, Po/Po/V, Po/Po/O, and C/O/O. The calibration curves were used to quantify the regioisomer compositions of selected TAGs in rapeseed oil, sunflower seed oil, palm oil, black currant seed oil, and sea buckthorn pulp oil. The method discriminates the different regioisomers and the results obtained by this method were in good agreement with previous results. This proves that this new method can be used for the determination of regiospecific distribution of fatty acids in TAGs.

Regioisomer compositions of vaccenic and oleic acid containing triacylglycerols in sea buckthorn (Hippophae rhamnoides) pulp oils: influence of origin and weather conditions.

Triacylglycerols (TAGs) 16:1(n-7)/16:1(n-7)/18:1(n-7) (Po/Po/V) and 16:1(n-7)/16:1(n-7)/18:1(n-9) (Po/Po/O) in pulp/peel oils of various sea buckthorn (Hippophae rhamnoides) subspecies and varieties were separated by reversed-phase high-performance liquid chromatography. The regioisomerism of the TAGs was determined by tandem mass spectrometry using ammonia supplemented in the nebulizer gas to produce ammonium adducts. The regioisomer compositions of Po/Po/V (8-24% of PoVPo) and Po/Po/O (43-61% of PoOPo) both differed from the random distribution of fatty acids (33.3% of ABA) in all 32 sea buckthorn samples investigated. The regioisomer compositions were different between cultivated ssp. rhamnoides varieties, wild ssp. rhamnoides, and wild ssp. sinensis. Differences were also found in the regioisomerism of both Po/Po/V and Po/Po/O between the two cultivated ssp. rhamnoides varieties, Tytti and Terhi. In addition, growth location and harvesting years showed clear impacts on the regioisomer compositions of Po/Po/V and Po/Po/O. Higher temperatures showed positive correlations with the proportion of PoOPo in ssp. rhamnoides and wild ssp. sinensis and with the proportion of sn-PoPoV+sn-VPoPo in wild ssp. sinensis. However, higher temperatures, higher temperature sums, and radiation sums increased the accumulation of PoVPo in wild ssp. rhamnoides.

Effect of latitude and weather conditions on the regioisomer compositions of alpha- and gamma-linolenoyldilinoleoylglycerol in currant seed oils.

The regioisomer compositions of triacylglycerols (TAG) 18:3(n-3)/18:2(n-6)/18:2(n-6) (Ala/L/L) and 18:3(n-6)/18:2(n-6)/18:2(n-6) (Gla/L/L) in seed oils of black and green currant ( Ribes nigrum L.) and red and white currant ( Ribes rubrum L.) varieties were determined by silver-ion high-performance liquid chromatography and mass spectrometry. The aim was to investigate whether latitude and weather conditions affect the regioisomer compositions of Ala/L/L and Gla/L/L and whether the regioisomerism differs between species and varieties. In R. rubrum the proportion of the symmetric regioisomer LAlaL among Ala/L/L was higher (14.1%) than in R. nigrum (12.1%) (p < 0.001). Generally in currants, the proportion of LAlaL was lower (p < 0.001) in northern Finland (12.1%) than in southern Finland (13.5%), where temperature and radiation sums were higher. In R. rubrum varieties grown in the south, the proportion of LGlaL among Gla/L/L was significantly higher in the years 2005 and 2007 (30.7-32.0%) than in 2006 (24.2-25.4%), when temperature and radiation sums were higher and the amount of precipitation was lower.