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Vineyard exposure to wildfire smoke can taint grapes and wine. To understand the impact of this taint, it is imperative that the analytical methods used are accurate and precise. This study compared the variance across nine commercial and research laboratories following quantitative analysis of the same set of smoke-tainted wines. In parallel, correlations between the interlaboratory consensus values for smoke-taint markers and sensory analyses of the same smoke-tainted wines were evaluated. For free guaiacol, the mean accuracy was 94 ± 11% in model wine, while the free cresols and 4-methylguaiacol showed a negative bias and/or decreased precision relative to guaiacol. Similar trends were observed in smoke-tainted wines, with the cresols and glycosidically bound markers demonstrating high variance. Collectively, the interlaboratory results show that data from a single laboratory can be used quantitatively to understand smoke-taint. Results from different laboratories, however, should not be directly compared due to the high variance between study participants. Correlations between consensus compositional data and sensory evaluations suggest the risk of perceivable smoke-taint can be predicted from free cresol concentrations, overcoming limitations associated with the occurrence of some volatile phenols, guaiacol in particular, as natural constituents of some grape cultivars and of the oak used for barrel maturation.

Phytohormones that trigger or repress flower meristem development in apple buds are thought to be locally emitted from adjacent plant tissues, including leaves and fruitlets. The presence of fruitlets is known to inhibit adjacent buds from forming flowers and thus fruits. The resulting absence of fruitlets the following season restores flower-promoting signalling to the new buds. The cycle can lead to a biennial bearing behaviour of alternating crop loads in a branch or tree. The hormonal stimuli that elicit flowering is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the cultivar 'Ruby Matilda' were subjected to zonal crop load treatments imposed to two leaders of bi-axis trees in the 2020/2021 season. Buds were collected over the expected FI phase, which is within 60 DAFB. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with FI in the leader and at tree level. Pronounced metabolic differences were observed in trees and leaders with high return bloom with significant increases in compounds belonging to the cytokinin, abscisic acid (ABA), phenylpropanoid and flavanol chemical classes. The presence of cytokinins, namely adenosine, inosine and related derivatives, as well as ABA phytohormones, provides further insight into the chemical intervention opportunities for future crop load management strategies via plant growth regulators. [ABSTRACT FROM AUTHOR]

The triggers of biennial bearing are thought to coincide with embryonic development in apple and occurs within the first 70 days after full bloom (DAFB). Strong evidence suggests hormonal signals are perceived by vegetative apple spur buds to induce flowering. The hormonal response is typically referred to as the floral induction (FI) phase in bud meristem development. To determine the metabolic pathways activated in FI, young trees of the biennial bearing cultivar 'Nicoter' and the less susceptible cultivar 'Rosy Glow' were forced into an alternate cropping cycle over five years and an inverse relationship of crop load and return bloom was established. Buds were collected over a four-week duration within 70 DAFB from trees that had maintained a four-year biennial bearing cycle. Metabolomics profiling was undertaken to determine the differentially expressed pathways and key signalling molecules associated with biennial bearing. Marked metabolic differences were observed in trees with high and low crop load treatments. Significant effects were detected in members of the phenylpropanoid pathway comprising hydroxycinnamates, salicylates, salicylic acid biosynthetic pathway intermediates and flavanols. This study identifies plant hormones associated with FI in apples using functional metabolomics analysis. [ABSTRACT FROM AUTHOR]

Purpose: Rising atmospheric CO2 levels associated with climate change increase plant nutrient demands. However, few studies have examined the interactions of atmospheric CO2 and P supply on root exudation which plays a crucial role in mobilising non-labile P in soil. This study aimed to examine the interactive effects of elevated CO2 and P deficiency on root exudation of organic acid anions and sugars over time. Methods: White lupin (Lupinus albus L.) was grown at 1, 5 and 50 µM P in solution culture under ambient (380 ppm) and elevated (700 ppm) CO2 levels. Root exudates were collected after 3, 4, 5 and 6 weeks of treatment, and organic acid anions and sugars were quantified using liquid chromatography-mass spectrometry. Results: Elevated CO2 and P deficiency positively interacted to enhance citrate exudation between 3 and 5 weeks of growth, while malate was only sporadically affected by elevated CO2 and fumarate remained unaffected. Elevated CO2 also increased exudation of glucose and fructose with larger increases being observed in P-deficient plants, which was largely constrained after 4 weeks. Elevated CO2 had no effect on exudation rates as plants matured. Conclusion: The positive interaction between CO2 and P deficiency led to increases in organic acid anion and sugar exudation, indicating that rising atmospheric CO2 levels could allow plants to access greater amounts of non-labile P when faced with P deficiency thereby reducing their reliance on non-renewable fertiliser inputs. [ABSTRACT FROM AUTHOR]

This work aimed to (i) determine the reliability of a portable Bluetooth colourimeter for fruit colour measurements; (ii) characterise the changes in quantitative skin colour attributes in a nectarine cultivar in response to time from harvest; and (iii) determine the influence of row orientation and training system on nectarine skin colour. The skin colour attributes measured with the colourimeter, namely L*, a* and b*, were calibrated and validated against a reference spectrophotometer. C* and h° were obtained from a* and b*. Skin colour was measured in situ from 42 days before to 6 days after harvest on 'Majestic Pearl' nectarines subjected to different row orientations and training systems. Validation models showed high reliability of colour estimations. The trends of colour attributes over time were characterised by cubic regression models, with h° proving to be the best parameter to describe changes of colour over time, with a clear link to the maturation process. No significant effects of row orientation and training system on skin colour were observed at harvest. Overall, the device proved reliable for fruit colour detection. Results of this study highlight the potential of h° as a quantitative index to monitor ripening prior to harvest in 'Majestic Pearl' nectarines. [ABSTRACT FROM AUTHOR]

Eighty-four crossbred wether and ewe lambs were allocated to four finishing diets. The diets were: Lucerne pasture (n = 24), Annual ryegrass with sub clover pasture (n = 18), Standard commercial feedlot pellets (n = 24) and Annual ryegrass based pasture and commercial feedlot pellets (500 g/day/head) (n = 18). After 8 weeks of feeding the lambs were slaughtered and the m. longissimus (LL) and m. semimembranosus (SM) were vacuum packaged and held chilled for 5 (fresh) or 60 (long aged) days, after which samples of each were displayed for 4 days under simulated retail conditions. Irrespective of muscle type the long aged samples exhibited a rapid reduction in redness (a*-values) and R630/580 nm ratio values such that consumer acceptable thresholds for both traits were quickly exceeded providing limited shelf life. Long ageing also lead to high TBARS levels measured as MDA mg/kg muscle suggestive of a product likely to exhibit rancidity and off flavours from lipid oxidation. [ABSTRACT FROM AUTHOR]

The influence of different pasture-based feeding systems on fatty acids, organic acids and volatile organic flavour compounds in yoghurt was studied. Pasture is the main source of nutrients for dairy cows in many parts of the world, including southeast Australia. Milk and milk products produced in these systems are known to contain a number of compounds with positive effects on human health. In the current study, 260 cows were fed supplementary grain and forage according to one of 3 different systems; Control (a traditional pasture based diet offered to the cows during milking and in paddock), PMR1 (a partial mixed ration which contained the same supplement as Control but was offered to the cows as a partial mixed ration on a feedpad), PMR 2 (a differently formulated partial mixed ration compared to Control and PMR1 which was offered to the cows on a feedpad). Most of the yoghurt fatty acids were influenced by feeding systems; however, those effects were minor on organic acids. The differences in feeding systems did not lead to the formation of different volatile organic flavour compounds in yoghurt. Yet, it did influence the relative abundance of these components. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different strategies for feeding supplements to grazing dairy cows on the proportions of fatty acids in milk. Two hundred and sixteen cows were fed supplementary grain and forage according to one of 3 different strategies; (1) Control: cows grazed perennial ryegrass pasture (14 kg dry matter/d) supplemented with milled barley grain fed in the milking parlour and pasture silage offered in the paddock; (2) Partial mixed ration 1 (PMR1): same pasture allotment and supplement as Control strategy, but the supplements presented as a mixed ration after each milking in feedpad, and; (3) Partial mixed ration 2 (PMR2): same pasture allotment, supplemented with a mixed ration of milled barley grain, alfalfa hay, corn silage and crushed corn grain fed in a feedpad. Within each strategy, cows were assigned to receive either 6, 8, 10 or 12 kg dry matter supplement/cow per d. Milk fatty acid proportions from cows fed Control and PMR1 strategies were similar and different from those fed PMR2, particularly at 10 to 12 kg dry matter supplement/cow per d. The reduction in milk fat yield and concentration in cows fed high amounts of supplement as Control and PMR1 was coincident with 4 × increase in 10t-18:1 proportion. The composition of the partial mixed ration (PMR) and the amount offered affected milk fatty acid proportions and milk fat content, however, the method of supplementation did not. [ABSTRACT FROM PUBLISHER]

Abstract: Bovine milk is considered to be a good dietary source of vitamins A, E and β-carotene. This paper describes a robust method for the simultaneous determination of these compounds using high performance liquid chromatography–ion trap mass spectrometry (HPLC–MS n ) as the determinative step. The compounds were separated with a 5μm Polaris 2.1×150mm C18-A column and an aqueous-methanol mobile phase and the levels determined using the MS2 fragments (vitamin A, m/z 213 and m/z 199, vitamin E m/z 165 and β-carotene m/z 413). The HPLC–MS n was operated in the positive ion APCI mode. The method was validated using repeatability studies, duplicate analyses, recovery experiments, proficiency study data and comparison with previously validated high performance liquid chromatographic ultraviolet/visible (HPLC–UV/Vis) and fluorescence (HPLC–Fl) procedures used in our laboratory. Expanded measurement uncertainties were similar for HPLC–MS n , HPLC–UV/Vis and HPLC–Fl, e.g. vitamin A 45μg/100ml, HPLC–MS n ±8%, HPLC–UV ±9%; vitamin E 150μg/100ml, HPLC–MS n ±11%, HPLC–Fl ±9%; β-carotene 12μg/100ml, HPLC–MS n ±18%, HPLC–Vis ±21%. [Copyright &y& Elsevier]

Abstract: A renewed international interest in vitamin D status has revealed significant deficiencies in several populations, including Australia. Vitamin D exists in two forms, cholcalciferol (D3) and ergocalciferol (D2). The main source of vitamin D3 is from exposure of 7-dehydrocholesterol present in the skin to UV irradiation. However, there is an absolute requirement for vitamin D through proper dietary intake if humans live in the absence of sunlight or exclusively indoors. Bovine milk is considered to be a good dietary source of vitamin D3, even though the levels are quite low. This paper describes robust methods using liquid chromatography–linear ion trap mass spectrometry (LC–MSn) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) to measure the levels of vitamin D3 in fresh bovine milk (0.05μg/100ml), commercial (natural and fortified) milk samples (0.01–2μg/100ml) and a dairy based infant formula (8μg/100g), without the need for extensive clean-up procedures. The limits of quantification (LOQ) are 0.01μg/100ml and 0.02μg/100ml for LC–MSn and LC–MS/MS, respectively. Recoveries of vitamin D3 added to the samples prior to saponification were satisfactory (range 60–90%). 25-Hydroxyvitamin D3 was not present in any of the samples analysed (LOQ=0.01μg/100ml, recovery range 30–40%). [ABSTRACT FROM AUTHOR]

This study investigated the impact of feeding pelleted diets containing camelina (Camelina sativa L. Crantz) hay (CAHP) or camelina meal (CAMP) as a supplement compared with a control pellet (CONP) diet, without vitamin E fortification. The fatty acid profile, retail colour, and lipid oxidative stability of lamb and yearling meat (m. longissimus lumborum) stored for short-, medium-, or long-periods (2 days (fresh), 45 days and 90 days) under chilled to semi-frozen conditions were determined. The CAMP diet altered key fatty acids (p < 0.05) in a nutritionally beneficial manner for human health compared to the other diets, with increased total omega-3, decreased omega-6 fatty acids and decreased omega-6/omega-3 ratio of muscle. Muscle vitamin E concentration was lower (p < 0.05) for both camelina diets (CAMP and CAHP) when compared with the CONP diet, with the average concentrations less than 1 mg/kg muscle for all three treatments. Animal type and storage length were factors that all affected (p < 0.05) colour and lipid oxidative stability of meat. These results emphasise the importance of vitamin E concentration in meat stored for extended periods under semi-frozen conditions to maintain desirable meat colour during retail display, and to avoid off-flavour development of the cooked meat. [ABSTRACT FROM AUTHOR]

Simple Summary: The increased incidence of heat stress in lambs has been reported in many countries, especially warmer parts of the world, compromising lamb welfare, having flow on effects for meat quality traits. While heat stress impacts can be variable depending on the severity and duration, the exposure of lambs to one week of elevated temperature increased the muscle omega-6 fatty acid concentration compared with the thermoneutral group. The one week heat stress is believed to enhance pro-inflammatory actions through induced free radical formation and oxidative stress. Somewhat independently, supplementation of the diet with vitamin E improved the growth rate and reduced oxidative stress. This suggests that under more extreme heat stress conditions, lambs fed in feedlots would benefit from enhanced levels of antioxidants such as vitamin E. The impact of antioxidant supplementation and short-term heat stress on lamb body weight gain, meat nutritional profile and functionality (storage stability of lipids and colour) of lamb meat was investigated. A total of 48 crossbred ((Merino × Border Leicester) × Dorset) lambs (42 ± 2 kg body weight, 7 mo age) were randomly allocated to three dietary treatments (n = 16) by liveweight (LW) that differed in dosage of vitamin E and selenium (Se) in the diet. Vitamin E and Se levels in the control (CON), moderate (MOD) and supranutritional (SUP) dietary treatments were 28, 130 and 228 mg/kg DM as α-tocopherol acetate and 0.16, 0.66 and 1.16 mg Se as SelPlex™/kg DM, respectively. After four weeks of feeding in individual pens, including one week of adaptation, lambs were exposed to two heat treatments. Animals were moved to metabolism cages for one week and subjected to heat treatments: thermoneutral (TN; 18–21 °C and 40–50% relative humidity) and heat stress (HS; 28–40 °C and 30–40% relative humidity) conditions, respectively. Final LW and hot carcass weight were influenced by dietary treatments with higher final live weight (FLW) (p = 0.05; 46.8 vs. 44.4 and 43.8 kg, respectively) and hot carcass weight (HCW) (p = 0.01; 22.5 vs. 21.3 and 21.0 kg, respectively) recorded in lambs fed the SUP as opposed to the CON and MOD diets. Vitamin E concentration in the longissimus lumborum (LL) muscle tended to be higher in lambs fed MOD or SUP diets than the CON group. Lipid oxidation of aged meat at 72 h of simulated retail display was reduced by antioxidant supplementation. Short-term (one week) heat stress treatment significantly increased muscle linoleic acid and total omega-6 concentrations compared with the CON group. The results demonstrate that four-week antioxidant supplementation at the SUP level improved animal productivity by increasing LW and carcass weight and the functionality of meat exhibited by reduced lipid oxidation. An increase in muscle omega-6 fatty acid concentration from short-term heat stress may induce oxidative stress via proinflammatory action. [ABSTRACT FROM AUTHOR]

The effect of feeding flaxseed or algae supplements to lambs on muscle antioxidant potential (vitamin E), major fatty acid groups, lipid oxidation and retail colour was investigated. Lambs (n = 120) were randomly allocated to one of 4 dietary treatments according to liveweight and fed the following diets for eight weeks: Annual ryegrass hay [60%] + subterranean clover hay [40%] pellets = Basal diet; Basal diet with flaxseed (10.7%) = Flax; Basal diet with algae (1.8%) = Algae; Basal diet with flaxseed (10.7%) and algae (1.8%) = FlaxAlgae. Flaxseed or algae supplementation significantly affected major fatty acid groups in muscle. The addition of algae (average of Algae and FlaxAlgae) resulted in lower vitamin E concentration in muscle ( P < 0.003; 1.0 vs 1.3 mg/kg of muscle) compared with lambs fed a diet without algae (average of Basal and Flax). Increasing muscle EPA + DHA by algae supplementation significantly increased lipid oxidation, but retail display colour of fresh meat was not affected. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to use metabolomic techniques to investigate the energy metabolism in lamb M. longissimus thoracis et lumborum subjected to very fast chilling (VFC) post-mortem . The tissue was prepared by 2 different operators and subjected to very fast chilling (less than 0 °C within 1.5 h of slaughter) or typical chilling regimes (Control; 0 °C within 22 h of slaughter). Non-targeted metabolomic analysis ( 1 H NMR) and targeted analysis ( 31 P NMR, HPLC-PDA and HPLC–MS/MS) were used to examine the change in muscle metabolites post-mortem . One VFC treatment, which resulted in a colder core temperature and more tender meat, had higher levels of glycolytic intermediate metabolites pre-rigor as well as more of the end-products of adenosine and nicotine nucleotide metabolism pre-rigor , relative to conventionally chilled treatments. In conclusion, VFC to less than 0 °C within 1.5 h of slaughter causes considerable changes in metabolism and rigor onset, which are associated with tender meat. [ABSTRACT FROM AUTHOR]

We investigated the association of muscle iron concentration, in addition to ultimate pH (pHU), on dark meat formation in sheep of different breeds fed forage-based diets. At 1 h simulated display, redness of meat (a*-value) increased (P <.0001) by about 3 units as the iron concentration increased from 10 to 22 mg/kg of meat, whereas the a*-value decreased by 2 units as pHU increased from 5.5 to 6.2 in fresh meat (P <.0001). After 90 days storage the corresponding responses were about 2 units increase for iron concentration and about 1 unit decrease for pHU, respectively. The results clearly show that increased muscle iron concentration was strongly associated with reduced dark cutting in fresh and stored meat evaluated at 1 h simulated display. We conclude that it may be desirable to measure iron concentration, along with pHU, for evaluation of the potential for carcasses to produce dark cutting meat, and for the meat to turn brown during display. • The association of muscle iron concentration and ultimate pH on redness of sheep meat at retail display was investigated • Increased muscle iron concentration was strongly associated with increased redness at 1 h retail display • The muscle iron effect on redness occurred both in fresh and in stored (aged) meat • The effect of muscle iron concentration was additive to the accepted effect of ultimate pH at 1 h retail display • There is a necessity to measure both iron concentration and ultimate pH when evaluating carcasses for dark cutting meat [ABSTRACT FROM AUTHOR]

Temperature-time combinations (TTC) effects on beef fatty acid (FA) composition, moisture content and oxidative traits were investigated. TTC were designed so temperatures were constant over each time period, and there was at most one variation in temperature within a sample's combined (total) time period. Therefore, three temperatures (~ 3, 5 and 7 °C) and five time periods (6, 8, 10 and 12 d) resulted in 72 different TTC, which were compared to control samples held for 14 d at ~ 1 °C. It was found that moisture losses increased as TTC temperature and time periods increased. There were negligible effects of TTC on FA composition. Sample TBARS and vitamin E content did not respond to TTC. A positive relationship between beef vitamin E and long chain polyunsaturated FA contents was observed. We concluded that TTC could be applied to accelerate the rate of ageing for beef and achieve comparable yield, oxidative and FA characteristics compared to conventional ageing approaches. [ABSTRACT FROM AUTHOR]

This study investigated the impact of feeding pelleted diets containing camelina ( Camelina sativa L. Crantz) hay (CAHP) or camelina meal (CAMP) as a supplement compared with a control pellet (CONP) diet, without vitamin E fortification. The fatty acid profile, retail colour, and lipid oxidative stability of lamb and yearling meat ( m. longissimus lumborum ) stored for short-, medium-, or long-periods (2 days (fresh), 45 days and 90 days) under chilled to semi-frozen conditions were determined. The CAMP diet altered key fatty acids ( p < 0.05) in a nutritionally beneficial manner for human health compared to the other diets, with increased total omega-3, decreased omega-6 fatty acids and decreased omega-6/omega-3 ratio of muscle. Muscle vitamin E concentration was lower ( p < 0.05) for both camelina diets (CAMP and CAHP) when compared with the CONP diet, with the average concentrations less than 1 mg/kg muscle for all three treatments. Animal type and storage length were factors that all affected ( p < 0.05) colour and lipid oxidative stability of meat. These results emphasise the importance of vitamin E concentration in meat stored for extended periods under semi-frozen conditions to maintain desirable meat colour during retail display, and to avoid off-flavour development of the cooked meat.