Pasteurization of citrus juices with ohmic heating to preserve the carotenoid profile

This study was carried out to assess, for the first time, the effect of ohmic heating on the carotenoid profile of two citrus fruit juices: grapefruit and blood orange. Two heat treatments were designed to obtain pasteurization values of 50 and 150 min (Tref = 70 °C and z-value = 10 °C) with ohmic heating as compared to conventional heating. The results showed that xanthophyll losses could reach 70% for epoxyxanthophylls (cis-violaxanthin and cis-antheraxanthin) and 40% for hydroxyxanthophylls (β-cryptoxanthin, lutein, and zeaxanthin) with conventional heating, but losses were under 30% and 20%, respectively, with ohmic heating. Carotene species (lycopene and β-carotene) were stable regardless of the treatment. No negative non-thermal effects of ohmic heating were shown on carotenoids. Loss simulations of the studied carotenoids showed that the high temperatures reached with ohmic heating during pasteurization could substantially increase the organoleptic and nutritional quality of acid carotenoid-rich juices.Industrial relevanceCitrus are the top fruit crops in terms of world trade. This craze for them -particularly orange and grapefruit- is notably due to their high content in organoleptic and nutritional compounds of interest and among them carotenoids. About 50% of the Citrus production is processed in juice. From the growing variety of products, minimal processed juices now have a significant market share. This work assessed for the first time the effect of ohmic heating, a thermal method for stabilizing juices while minimizing the impact on the juice quality, on the carotenoid profiles of blood orange and grapefruit juice. Pasteurization with ohmic heating was proven to be a very good alternative for protecting carotenoids and especially xanthophylls compared to conventional heating. These results will help in designing ohmic heating process parameters for optimizing the overall quality of carotenoid-rich fruit juices.     

Assessment of conventional and microwave heating induced degradation of carotenoids in olive oil by VIS Raman spectroscopy and classical methods

Raman spectroscopy, as a fast non-destructive method, has shown its potential in revealing heat-induced degradation of extra virgin olive oil carotenoids during microwave versus conventional heating processes. A progressive degradation in carotenoids was observed, starting at 180 °C and 140 °C in microwave and conventional heating processes respectively; this was followed by a rapid degradation at 180 °C only with conventional heating. As the main difference, the Raman bands due to carotenoids completely disappeared at 203 °C with conventional heating, while these bands could still be observed even up to 225 °C with microwave heating. Furthermore a loss of cis double bonds and slightly changes in free fatty acid was also observed in both heating processes. A precise calibration model was established using partial least squares regression, which can be used for monitoring carotenoids content degradation during heating. The accuracy of the model was estimated using the root mean square errors and the correlation coefficient.     

Effect of incremental amounts of camelina oil on milk fatty acid composition in lactating cows fed diets based on a mixture of grass and red clover silage and concentrates containing camelina expeller

Camelina is an ancient oilseed crop that produces an oil rich in cis-9,cis-12 18:2 (linoleic acid, LA) and cis-9,cis-12,cis-15 18:3 (α-linolenic acid, ALA); however, reports on the use of camelina oil (CO) for ruminants are limited. The present study investigated the effects of incremental CO supplementation on animal performance, milk fatty acid (FA) composition, and milk sensory quality. Eight Finnish Ayrshire cows (91 d in milk) were used in replicated 4 × 4 Latin squares with 21-d periods. Treatments comprised 4 concentrates (12 kg/d on an air-dry basis) based on cereals and camelina expeller containing 0 (control), 2, 4, or 6% CO on an air-dry basis. Cows were offered a mixture of grass and red clover silage (RCS; 1:1 on a dry matter basis) ad libitum. Incremental CO supplementation linearly decreased silage and total dry matter intake, and linearly increased LA, ALA, and total FA intake. Treatments had no effect on whole-tract apparent organic matter or fiber digestibility and did not have a major influence on rumen fermentation. Supplements of CO quadratically decreased daily milk and lactose yields and linearly decreased milk protein yield and milk taste panel score from 4.2 to 3.6 [on a scale of 1 (poor) to 5 (excellent)], without altering milk fat yield. Inclusion of CO linearly decreased the proportions of saturated FA synthesized de novo (4:0 to 16:0), without altering milk fat 18:0, cis-9 18:1, LA, and ALA concentrations. Milk fat 18:0 was low (<5 g/100 g of FA) across all treatments. Increases in CO linearly decreased the proportions of total saturates from 58 to 45 g/100 g of FA and linearly enriched trans-11 18:1, cis-9,trans-11 18:2, and trans-11,cis-15 18:2 from 5.2, 2.6, and 1.7 to 11, 4.3, and 5.8 g/100 g of FA, respectively. Furthermore, CO quadratically decreased milk fat trans-10 18:1 and linearly decreased trans-10,cis-12 18:2 concentration. Overall, milk FA composition on all treatments suggested that one or more components in camelina seeds may inhibit the complete reduction of 18-carbon unsaturates in the rumen. In conclusion, CO decreased the secretion of saturated FA in milk and increased those of the trans-11 biohydrogenation pathway or their desaturation products. Despite increasing the intake of 18-carbon unsaturated FA, CO had no effect on the secretions of 18:0, cis-9 18:1, LA, or ALA in milk. Concentrates containing camelina expeller and 2% CO could be used for the commercial production of low-saturated milk from grass- and RCS-based diets without major adverse effects on animal performance.     

Analysis of Anabaena vaginicola and Nostoc calcicola from Northern Iran,as rich sources of major carotenoids

Four major carotenoids of high nutritional significance, including β-carotene, lycopene, lutein and zeaxanthin were determined in three isolates of heterocystous cyanobacteria, belonging to the genera Anabaena and Nostoc, isolated from Iranian terrestrial and aquatic ecosystems, for the first time. The ultrasonically extracted carotenoids were identified and quantified by a rapid and sensitive isocratic HPLC method and identification was further confirmed by spiking authentic standards and the pattern of the UV–Vis spectra obtained from photo-diode array detector. The results showed that these isolates contain large amounts of four major carotenoids, especially lycopene (up to 24570 μg/g dry weight, DW) which appears to be the highest reported amount until present; and β-carotene (up to 8133 μg/g DW) which is comparable with the best natural sources of β-carotene. Meanwhile, they are rich in the cis-isomers of lycopene and β-carotene which is important in their bioavailability and health benefits.     

An in vitro model to study the intestinal absorption of carotenoids

An in vitro cell culture model to assess the intestinal absorption of carotenoids is described. When supplemented with taurocholate and oleic acid, differentiated Caco-2 cells on membranes are able to produce chylomicrons. Under conditions mimicking the in vivo postprandial state, Caco-2 cells take up carotenoids and secrete them incorporated into chylomicrons; the extents of absorption of all-trans, 9-cis, 13-cis β-carotene, α-carotene, lutein, lycopene were 11%, 2%, 3%, 10%, 7%, and 3%, respectively. Saturation of β-carotene transport through Caco-2 cells occurred at concentrations (>15 μM) higher than “physiological” concentrations. Finally, retinol supplementation resulted in an 1.7-fold increase in β-carotene transport. The data suggest that (1) the intestinal absorption of carotenoids is facilitated by the participation of a specific epithelial transporter and (2) retinol promotes β-carotene incorporation into larger, retinyl ester-enriched chylomicrons. The present in vitro cell culture system is a relevant model to study the intestinal absorption of carotenoids at the molecular level.     

Impact of ropy and capsular exopolysaccharide-producing strains of Lactococcus lactis subsp. cremoris on reduced-fat Cheddar cheese production and whey composition

Cheddar cheese mixed starter cultures containing exopolysaccharide (EPS)-producing strains of Lactococcus lactis subsp. cremoris (Lac. cremoris) were characterized and used for the production of reduced-fat Cheddar cheese (15% fat). The effects of ropy and capsular strains and their combination on cheese production and physical characteristics as well as composition of the resultant whey samples were investigated and compared with the impact of adding 0.2% (w/v) of lecithin, as a thickening agent, to cheese milk. Control cheese was made using EPS-non-producing Lac. cremoris. Cheeses made with capsular or ropy strains or their combination retained 3.6–4.8% more moisture and resulted in 0.29–1.19 kg/100 kg higher yield than control cheese. Lecithin also increased the moisture retention and cheese yield by 1.4% and 0.37%, respectively, over the control cheese. Lecithin addition also substantially increased viscosity, total solid content and concentrating time by ultra-filtration (UF) of the whey produced. Compared with lecithin addition, the application of EPS-producing strains increased the viscosity of the resultant whey slightly, while decreasing whey total solids, and prolonging the time required to concentrate whey samples by UF. The amount of EPS expelled in whey ranged from 31 to 53 mg L⁻¹. Retention of EPS-producing strains in cheese curd was remarkably higher than that of non-producing strains. These results indicate the capacity of EPS-producing Lac. cremoris for enhanced moisture retention in reduced-fat Cheddar cheese; these strains would be a promising alternative to commercial stabilizers.     

Evaluation of extraction method for the analysis of carotenoids in fruits and vegetables

This study evaluated a suitable extraction method for a wide range of sample matrices in carotenoid analysis. Using canned tomato juice as a representative sample, it is shown that two solvents of low biological hazard, ethanol and hexane are the most suitable for extracting carotenoids from the matrix. The use of double extraction, each with 35 ml of ethanol:hexane mixture (4:3, by volume), resulted in good recoveries of carotenoids (lycopene 96%, α-carotene 102% and β-carotene 93–100%). Coefficients of variation conducted on different days were: lycopene 5% and β-carotene 7%. An application of the established method to various kinds of fruit and vegetable matrices is also shown, using carrot and spinach as representative samples of root and leafy vegetables, for determining recoveries of added carotenoids. The average percent recoveries of added carotenoids from canned tomato juice, carrot and spinach were: 101, 99.8 and 101% for α-carotene (12.4, 24.8, 49.6 and 99.2 μg/10 ml of added α-carotene); and 98.1, 99.7 and 96.1 percent for β-carotene (25.5, 50.9, 101 and 201 μg/10 ml of added β-carotene). These similar recoveries over the explored concentration ranges confirm that the application of established extraction method is unaffected by differences in matrix composition of the samples.     

Effect of pH and level of concentrate in the diet on the production of biohydrogenation intermediates in a dual-flow continuous culture

Milk fat depression in cows fed high-grain diets has been related to an increase in the concentration of trans-10 C_18:1 and trans-10,cis-12 conjugated linoleic acid (CLA) in milk. These fatty acids (FA) are produced as a result of the alteration in rumen biohydrogenation of dietary unsaturated FA. Because a reduction in ruminal pH is usually observed when high-concentrate diets are fed, the main cause that determines the alteration in the biohydrogenation pathways is not clear. The effect of pH (6.4 vs. 5.6) and dietary forage to concentrate ratios (F:C; 70:30 F:C vs. 30:70 F:C) on rumen microbial fermentation, effluent FA profile, and DNA concentration of bacteria involved in lipolysis and biohydrogenation processes were investigated in a continuous culture trial. The dual-flow continuous culture consisted of 2 periods of 8 d (5 d for adaptation and 3 d for sampling), with a 2 × 2 factorial arrangement of treatments. Samples from solid and liquid mixed effluents were taken for determination of total N, ammonia-N, and volatile fatty acid concentrations, and the remainder of the sample was lyophilized. Dry samples were analyzed for dry matter, ash, neutral and acid detergent fiber, FA, and purine contents. The pH 5.6 reduced organic matter and fiber digestibility, ammonia-N concentration and flow, and crude protein degradation, and increased nonammonia and dietary N flows. The pH 5.6 decreased the flow of C_18:0, trans-11 C_18:1 and cis-9, trans-11 CLA, and increased the flow of trans-10 C_18:1, C_18:2n-6, C_18:3n-3, trans-11,cis-15 C_18:2 and trans-10,cis-12 CLA in the 1 h after feeding effluent. The pH 5.6 reduced Anaerovibrio lipolytica (32.7 vs. 72.1 pg/10 ng of total DNA) and Butyrivibrio fibrisolvens vaccenic acid subgroup (588 vs. 1,394 pg/10 ng of total DNA) DNA concentrations. The high-concentrate diet increased organic matter and fiber digestibility, nonammonia and bacterial N flows, and reduced ammonia-N concentration and flow. The high-concentrate diet reduced trans-11 C_18:1 and trans-10 C_18:1, and increased C_18:2n-6, C_18:3n-3 and trans-10,cis-12 CLA proportions in the 1 h after feeding effluent. The increase observed in trans-10,cis-12 CLA proportion in the 1 h after feeding effluent due to the high-concentrate diet was smaller that that observed at pH 5.6. Results indicate that the pH is the main cause of the accumulation of trans-10 C_18:1 and trans-10, cis-12 CLA in the effluent, but the trans-10,cis-12 CLA proportion can be also affected by high levels of concentrate in the diet.     

Effect of two ethnic processing technologies on reduction and composition of total and non-glucosidic cyanogens in cassava

The effectiveness of two different processing methods on reduction of total and non-glucosidic cyanogens in cassava was studied in two ethnic groups in Nkhota Kota, Malawi. Cassava cyanogen content was periodically monitored during processing. Total cyanogen reductions of 97.9 ± 0.5% and 82.4 ± 1.0% were obtained upon soaking peeled and unpeeled roots, respectively. The residual cyanogen content (2.6 ± 0.7 mg HCN eq./kg) in flour produced from peeled roots was lower than the FAO/WHO limit (10 mg HCN eq./kg). The flour from the unpeeled method contained twenty times more residual cyanogen levels (53.8 ± 1.8 mg HCN eq./kg dry matter). The peels exhibited four times higher cyanohydrin than the pulp. Inclusion of the peel during processing therefore leads to high retention of cyanogens in the pulp. Clearly, soaking of peeled roots is a more effective method and thus should be promoted among ethnic communities that soak unpeeled roots.     

Effect of heat treatment on the content of some bioactive compounds and free radical-scavenging activity in pungent and non-pungent peppers

Raw and heat-treated (boiled and grilled) pungent and non-pungent peppers (poblano, bell, chilaca, caribe, jalapeño, serrano, habanero and manzano) were evaluated for their content of some bioactive compounds and free radical-scavenging activity. Boiling and grilling were performed under household conditions. Ascorbic acid content in raw peppers varied from 306 to 3438 μg/g. This content was reduced 15–87% by heat treatments. Total carotenoids content in raw peppers ranged between 1 and 156 μg/g. β-Carotene represented 3–78% of total carotenoids in raw peppers. β-Carotene content was reduced (1–45%) by heat treatments. Free radical-scavenging activity varied widely (7–101 μmol TE/g) in raw peppers. Boiling and grilling reduced (6–93%) sequentially the antiradical activity of pungent peppers. In contrast, gradual increases of antiradical activity in non-pungent peppers were induced by boiling and grilling. Household heat treatment altered highly the content of bioactive/antioxidant compounds in tested peppers.     

Effect of processing on the retention of carotenoids in yellow‐fleshed cassava (Manihot esculenta Crantz) roots

The retention of carotenoids was studied in roots from yellow‐fleshed, high carotene cassava clones in four different processing methods. The results indicated that the extent of retention varied with the method of processing. The highest retention was observed in oven drying (total carotenoids 54.70–84.01% and β‐carotene 63.90–94.53%) followed by boiling (total carotenoids 47.87–83.79% and β‐carotene 51.31–81.04%) and frying (total carotenoids 48.76–79.77% and β‐carotene 44.11–83.87%). The lowest retention of total carotenoids (32.86–56.40%) and β‐carotene (21.47–56.68%) was recorded in the sun drying method. The variation in the total carotenoids and β‐carotene content depends on variety, processing method and initial carotene content of the fresh root.     

Carotenoid content,its stability during drying and the antioxidant activity of commercial coriander (Coriandrum sativum L.) varieties

Although populations of several tropical countries are under severe vitamin-A deficiency, traditional sources of pro-vitamin-A carotenoids have not been exploited due to the lack of relevant research data. In this study, ten commercial varieties of coriander (Coriandrum sativum L.), grown at identical conditions, were evaluated for carotenoids, their bio-efficacy and stability during drying, with the main emphasis on β-carotene (vitamin-A precursor) analysis by HPLC-MS. In all varieties, β-carotene content was higher in foliage at mature stage, than in seedlings and seeds. Variety GS4 Multicut produced highest biomass (6.18 ± 0.73 g/plant), total carotenoids (217.50 ± 5.6 mg/100 g DW) and β-carotene (73.64 ± 0.3 mg/100 g DW) at pre-flowering stage. Carotenoids extract showed a high antioxidant activity with IC₅₀ value of 14.29 ± 1.68 μg/ml, scavenging hydroxyl radicals and rendering higher protection to DNA than by standard gallic acid (IC₅₀ = 357.21 ± 4.29). Microwave drying of foliage was rapid with better retention of pigments, high intactness of trans-β-carotene and higher extractability of pigments when compared with oven drying.     

Carotenoid transfer to oil during thermal processing of low fat carrot and tomato particle based suspensions

Carotenoid solubilization in the oil phase is a prerequisite for carotenoid bioaccessibility during digestion. However, the level of bioencapsulation and the hydrophobicity of carotenoids were proven to strongly affect their transfer to oil during in vitro digestion. Therefore, thermal processing (95–110 °C) was exploited to favor carotenoid transfer from tomato- and carrot-based fractions to the oil before digestion. Initially, the total (all-trans + cis) carotenoid content in the oil increased quickly, thereafter, depending on the temperature applied, either a drop or a plateau was reached at longer treatment times. Treatment conditions of > 100 °C for 10 min significantly favoured carotenoid transfer to oil (≥ 75%). The rates of transfer to oil were as follows: β-carotene ≈ α-carotene > lycopene. The results revealed that the cell wall hinders carotenoid transfer to oil during thermal processing. Overall, the results indicate that typical high temperature short time thermal processing can be sufficient to achieve maximal carotenoid transfer to oil with minimal degradation in real food systems/food emulsions and this can be crucial to improve the nutritional quality of carrot and tomato based products.     

Mastication effects on carotenoid bioaccessibility from mango fruit tissue

The release of carotenoids from fresh fruits or vegetables is determined by the encapsulating plant tissue matrix, intracellular carotenoid location within the cell, and the mastication process. The objectives of this study were to assess the particle sizes obtained after mastication of mango fruit tissue, and how the resulting degree of plant tissue rupture affects carotenoid bioaccessibility. A fine and a coarse chewer were selected after screening 20 healthy volunteers for in vivo human mastication, and the collected chewed boluses were subjected to wet sieving fractionation, followed by an in vitro gastric and small intestinal digestion model. Confocal micrographs show that the smallest particle size fraction (0.075 mm) consists mostly of fragmented cells and the largest size fraction (2.8 mm) contains bulky clusters of whole cells and vascular fibers. Higher amounts of total carotenoids (211–320 μg/100 g) were observed in the larger particle size fraction (2.8 mm) relative to the 1 mm (192–249 μg/100 g) and 0.075 mm fractions (136–199 μg/100 g). Smaller particles showed a greater % release of total carotenoids after in vitro digestion. Xanthophyll derivatives are more bioaccessible than β-carotene for all particle sizes. The effects of particle size or degree of fine vs coarse chewing are unexpectedly small (p > 0.05), but the process of chewing substantially reduced the release of β-carotene and xanthophylls by 34% and 18%, respectively. While there is a (small) particle size effect, this appears to not be the primary factor controlling bioaccessibility for soft tissues such as mango, in contrast to previous reports that a single cell wall appears to be enough to prevent bioaccessibility of carotenoids in more robust carrot tissues.     

Carotenoids in crabs from marine and fresh waters of India

Quantitative and qualitative distribution of carotenoids in meat and shell of major marine crab (Charybdis cruciata) and fresh water crab (Potamon potamon) from Indian waters was assessed. The total carotenoid content was low in both species of crabs analysed, highest being 11.0 μg/g in shell of marine crab. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) of carotenoid extracts indicated that the marine crab contained astaxanthin and its esters as major carotenoids and zeaxanthin was major carotenoid in fresh water crab extract. Astaxanthin and its esters contributed 67.6 and 65.5 g/100 g of total carotenoids in meat and shell of marine crab. The zeaxanthin content (g/100 g) in the carotenoid extract of meat and shell of fresh water crab was 42.0 and 74.8 of total carotenoids. The carotenoid extracts from both the crabs had higher level of unsaturated fatty acids. Oleic acid (C18:1) and palmitoleic acid (C16:1) were the predominant unsaturated fatty acid in carotenoid extract from meat of marine and fresh water crab, respectively. In the carotenoid extract from shell, eicosenoic acid (C20:1) in marine crab and linolenic acid (C18:3) in fresh water crab were the major unsaturated fatty acids.     

Polyphenolic and antioxidant content of white and blue corn (Zea mays L.) products

The polyphenolic and antioxidant content of white, Mexican blue, and American blue corns processed into nixtamal (cooked kernels), tortillas, and chips was investigated. A post-nixtamalization acidification treatment was assessed as a means to reduce polyphenolic and antioxidant losses. Similar anthocyanin composition (cyanidin 3-monoglycosides) and concentration (314 mg/kg) was observed for both blue corn genotypes as was their non-anthocyanin polyphenolic composition ((+)-catechin, free and esterified ferulic acid, and p-coumaric acid derivatives). Six derivatives of ferulic acid (88.8–816 mg/kg) along with the free form (2480 mg/kg), p-coumaric acid (6.6 mg/kg), two protocatechuic acid derivatives (4.2 and 14.2 mg/kg), and gallic acid (3.9 mg/kg) were identified in the white genotype. Both blue genotypes contained higher antioxidant capacity (>8.3 μmol Trolox equivalents/g) yet lower polyphenolic levels (3.6–4.4 g/kg) than the white genotype. Comparable anthocyanin losses were observed when the blue genotypes were processed into nixtamals (37%), tortillas (54%), and chips (78%) that correlated to polyphenolic (r = 0.91) and antioxidant capacity (r = 0.94) losses. Acidification was mainly effective in reducing anthocyanin (9–17%), polyphenolic (10%), and antioxidant capacity (6–14%) losses for the blue genotypes. This study compared polyphenolic and antioxidant content among corn genotypes and confirmed that acidification post-nixtamalization could reduce polyphenolic and antioxidant losses.     

Proximate,Functional and Anti-Nutritional Properties of Boiled Ukpo Seed (Mucuna flagellipes) Flour

“Ukpo” (Mucuna flagellipes) seed flour is one of the soup thickeners used in most rural Igbo-speaking communities of Southern Nigeria. Its preparation is usually associated with long cooking time which is required to soften the cotyledon before grinding as well as reduce the anti-nutritional components of the seed. This work was therefore aimed at determining the effect of boiling time on some functional properties and antinutritional properties of the ukpo seed flour. The result obtained showed that there were slight reductions in the protein, fat and ash content as boiling time increased probably due to leaching. All the functional properties analysed increased significantly (p ≤ 0.05) with increasing boiling time. The water absorption, oil absorption and emulsion capacities increased from values of 1.60 ml/g, 1.23 ml/g and 9.3 ml/g respectively at 0 minutes to 3.2 ml/g, 2.8 ml/g and 17.66 ml/g respectively at 60 minutes. The bulk density and swelling index also increased from 0.72 g/ml to 1.17 cm³/cm³ and from 1.02 g/ml to 1.36 cm³/cm³ respectively. The oxalate, tannin, saponin, phenol and phytate contents decreased significantly (p ≤ 0.05) with increasing boiling time. The values at 60 minutes boiling time were 0.14%, 0.182%, 0.434%, 0.146% and 0.719% respectively. These results suggest that heat treatment improves the performance of the Ukpo flour in soup thickening while reducing to a large extent the anti-nutritional properties.     

Thermal processing of carrots: Lycopene stability and isomerisation with regard to antioxidant potential

The thermal stability of lycopene was evaluated in a carrot cultivar with a high lycopene content (Daucus carota var. Nutri Red) by (a) exposure of carrot homogenates (with/without the addition of oil) to temperatures ranging from 25 to 140 °C; (b) applying convection and microwave vacuum drying to carrot slices. Heating carrot homogenates at temperatures above 100 °C initiated isomerisation of all-trans-lycopene under non-oxidising conditions, as indicated by a significant increase in 9-cis-lycopene. Isomerisation was enhanced at short treatment times, when sunflower oil was added prior to thermal treatment. Independent from an oil supplement, all-trans-lycopene was degraded at temperatures above 70 °C. The ratio of all-trans- to total-cis-isomers changed from 90:10 to 40:60, indicating a higher lycopene bioavailability due to generated cis-isomers. In oil containing carrot homogenates antioxidant properties of the methanol-soluble components raised after heat treatment at 130 °C for 0.5 h. Lycopene remained stable in dried carrots.     

Effect of a dual-purpose inoculant on the quality and nutrient losses from corn silage produced in farm-scale silos

This project aimed to determine effects of applying an inoculant containing homofermentative and heterofermentative bacteria on the fermentation, nutritive value, aerobic stability, and nutrient losses from corn silage produced in farm-scale silos. Corn forage was harvested at 34% dry matter (DM) and treated without (control) or with 5 × 10⁵ cfu/g of Lactobacillus buchneri and Pediococcus pentosaceus. The inoculant was sprayed on alternate 8-row-wide swaths of forage, and the untreated and inoculated forages were alternately packed into 3.6-m-wide bag silos. Forty-five tonnes of corn forage were packed into each of 4 replicate bags per treatment and ensiled for 166 d. Silage removed from the bags (500 kg/d) was separated into good and spoiled (visibly moldy or darker) silage portions, and weighed for 35 d. Weekly composites were analyzed for chemical composition, aerobic stability, and fungal counts. Aerobic stability was measured using data loggers that recorded sample and ambient temperature every 30 min for 7 d. Inoculation did not affect the chemical composition of the spoiled or good silage but decreased the quantity (5.7 vs. 12.9 kg/d) and percentage (3.4 vs. 7.8) of spoiled silage in the bags by over 50%. Losses of crude protein (0.28 vs. 0.92 kg/d), gross energy (6.0 × 10⁴ vs. 1.8 × 10⁵ kJ/d), and neutral detergent fiber (1.34 vs. 4.12 kg/d) in spoiled silage were less in inoculated versus control silages. Inoculated silages had lower pH (3.91 vs. 3.99), lactate concentration (7.63 vs. 7.86%), lactate:acetate ratio (1.58 vs. 2.53%), and a greater acetate (5.11 vs. 3.56%) concentration than the control silage. Inoculated silages tended to have fewer yeasts (2.59 vs. 4.62 log cfu/g) than control silages, but aerobic stability was not different across treatments (14.7 vs. 9.5 h). Applying the inoculant made the fermentation more heterolactic, inhibited the growth of yeasts, and substantially reduced the amount of spoilage and the associated energy and nutrient losses.     

Effects of chestnut tannins on carcass characteristics,meat quality,lipid oxidation and fatty acid composition of rabbits

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P < 0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P < 0.01), palmitoleic acid (C16:1 cis-9; P < 0.05) and pentadecanoic acid (C15:0; P < 0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P < 0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P < 0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n − 6/n − 3 ratios among the groups.