Investigation of Pulsed Electric Field Conditions at Low Field Strength for the Tenderisation of Beef Topside.

Tenderness is the most critical eating quality trait of meat, and consequently, processing interventions for meat tenderisation have significant economic relevance. The objective of this study was to investigate pulsed electric field (PEF) conditions for the tenderisation of beef topside. The PEF settings included combinations of three field strengths (0.25, 0.50 and 1.00 kV/cm), two frequencies (20 and 100 Hz) and three treatment times (10, 30 and 50 ms). The effect of PEF on meat quality parameters (pH, drip loss, shear force, cook loss and colour) immediately after treatment and after storage (1 and 14 days at 4 °C) was evaluated. PEF did not affect meat tenderness after 1 day of chilled storage but resulted in a 5-10% reduction in the shear force in some cases (0.25-0.5 kV/cm) compared to the untreated control after 14 days of storage. Other quality traits (cook loss and colour) were not impaired. Thus, we concluded that PEF technology is a possible intervention to improve meat tenderness of beef topside after 2 weeks of storage.

Long term food stability for extended space missions: a review.

At present, human spaceflight is confined to low Earth orbit but, in future, will again go to the Moon and, beyond, to Mars. The provision of food during these extended missions will need to meet the special nutritional and psychosocial needs of the crew. Terrestrially grown and processed food products, currently provided for consumption by astronauts/cosmonauts, have not yet been systematically optimised to maintain their nutritional integrity and reach the shelf-life necessary for extended space voyages. Notably, space food provisions for Mars exploration will be subject to extended exposure to galactic cosmic radiation and solar particle events, the impact of which is not fully understood. In this review, we provide a summary of the existing knowledge about current space food products, the impact of radiation and storage on food composition, the identification of radiolytic biomarkers and identify gaps in our knowledge that are specific in relation to the effect of the cosmic radiation on food in space.

Rapid Evaporative Ionization Mass Spectrometry: A Review on Its Application to the Red Meat Industry with an Australian Context.

The red meat supply chain is a complex network transferring product from producers to consumers in a safe and secure way. There can be times when fragmentation can arise within the supply chain, which could be exploited. This risk needs reduction so that meat products enter the market with the desired attributes. Rapid Evaporative Ionisation Mass Spectrometry (REIMS) is a novel ambient mass spectrometry technique originally developed for rapid and accurate classification of biological tissue which is now being considered for use in a range of additional applications. It has subsequently shown promise for a range of food provenance, quality and safety applications with its ability to conduct ex vivo and in situ analysis. These are regarded as critical characteristics for technologies which can enable real-time decision making in meat processing plants and more broadly throughout the sector. This review presents an overview of the REIMS technology, and its application to the areas of provenance, quality and safety to the red meat industry, particularly in an Australian context.

Contemporary chemical lean determination used in the Australian meat processing industry: A method comparison.

Chemical Lean (CL) is defined as the amount of lean red meat compared to the amount of fat in a meat product. CL determination is a mandatory, AUS-MEAT Ltd. prescribed requirement for any bulk packed meat product destined for export. Fifteen methods are approved by AUS-MEAT Ltd., for use in Australian industry. Engagement with Australian meat processors indicated that a range of methods were used for CL measurements in industry, ranging from wet chemical to instrumental based techniques. Meat (consisting of beef, lamb and pork) was used in a method comparison which included Soxhlet fat extraction and microwave moisture analysis, along with instrumental techniques; near infrared reflectance and transmittance, nuclear magnetic resonance and X-Ray. The methods were compared using Passing-Bablok regression, Bland-Altman plot analysis, and robust z-scores, indicating that overall showed that each method performed satisfactorily, suitable for CL determination in the Australian meat industry.

Bioactivity and health effects of ruminant meat lipids. Invited Review.

Ruminant meat (RM) is an excellent source of high-quality protein, B vitamins and trace minerals and plays an important role in global food and nutrition security. However, nutritional guidelines commonly recommend reduced intake of RM mainly because of its high saturated fatty acid (SFA) content, and more recently because of its perceived negative environmental impacts. RM is, however, rich in heart healthy cis-monounsaturated fatty acids and can be an important source of long-chain omega-3 (n-3) fatty acids in populations with low fish consumption. In addition, RM is a source of bioactive phospholipids, as well as rumen-derived bioactive fatty acids including branched-chain, vaccenic and rumenic acids, which have been associated with several health benefits. However, the role of bioactive RM lipids in maintaining and improving consumers' health have been generally ignored in nutritional guidelines. The present review examines RM lipids in relation to human health, and evaluates the effectiveness of different feeding strategies and possibilities for future profile and content improvement.

Characterization of Four Alkyl-branched Fatty Acids as Methyl, Ethyl, Propyl, and Butyl Esters Using Gas Chromatography-Quadrupole Time of Flight Mass Spectrometry.

Branched fatty chain fatty acids (BCFAs) are associated with the "mutton flavor" found with the aroma resulting from cooked older sheep meat with three BCFAs, 4-methyloctanoic (MOA), 4-ethyloctanoic (EOA) and 4-methylnonanoic (MNA) acids as the main compounds responsible for "mutton flavor". Usually, BCFA analysis is done by gas chromatography (GC) with the use of quadrupole mass spectrometry (qMS) becoming predominant. 2-Butyloctanoic acid (2BO) has been used in this facility using as an internal standard to determine BCFA content in sheep fat. In this present work, GC-qMS, along with GC-quadrupole-time of flight MS (GC-QTOF-MS), have been deployed to characterize alkyl esters (as methyl, ethyl, propyl, and butyl) for MOA, EOA, MNA, and 2BO. This work presents, for the first time, the mass spectral characterization of 2BO for these alkyl esters using GC-qMS and GC-QTOF-MS.

Heptadecanoic acid as an indicator of BCFA content in sheep fat.

Branched chain fatty acids (BCFAs) are associated with 'mutton flavour' found in cooked sheep meat aroma. Three BCFAs, 4-methyloctanoic (MOA), 4-ethyloctanoic (EOA) and 4-methylnonanoic (MNA) acids, have been implicated as the main compounds responsible for 'mutton flavour'. Animal age can also contribute to increasing BCFA concentration. Heptadecanoic acid (C17:0 FA) also increases with animal age in sheep. Using published data, a linear association has been found to exist between C17:0 FA with MOA and MNA in sheep fat, with C17:0 FA increasing proportionally with these two compounds. No association was found between C17:0 FA and EOA. As C17:0 FA is present in sheep fat in relatively higher proportions compared to BCFAs, it has potential to be used as a proxy for MOA and MOA as well as 'mutton flavour'.

Discrimination of Aroma Characteristics for Cubeb Berries by Sensomics Approach with Chemometrics.

The dried cubeb berries are widely used as medicinal herb and spicy condiment with special flavor. However, there is a significant definition discrepancy for cubeb berries. In this study, an efficient analytical method to characterize and discriminate two popular cubeb fruits (Litsea cubeba and Piper cubeba) was established. The aroma profiles of cubeb berries were evaluated by different extraction methods including hydro-distillation, simultaneous distillation/extraction, and solid-phase micro-extraction followed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). In total, 90 volatile compounds were identified by HD, SDE, and SPME combined with GC-MS. Principal component analysis was further applied and discriminated ambiguous cubeb berries by their unique aromas: Litsea cubeba was characterized by higher level of d-limonene ("fruit, citrus"), citral ("fruit, lemon") and dodecanoic acid; α-cubebene ("herb") was identified as a marker compound for Piper cubeba with higher camphor ("camphoraceous"), and linalool ("flower"). Flavor fingerprint combined with PCA could be applied as a promising method for identification of cubeb fruits and quality control for food and medicinal industries.

Impact of Brassica and Lucerne Finishing Feeds and Intramuscular Fat on Lamb Eating Quality and Flavor. A Cross-Cultural Study Using Chinese and Non-Chinese Australian Consumers.

Use of forage brassicas (Brassica napus) and lucerne (alfalfa; Medicago sativa) as ruminant feeds has been linked to unacceptable flavors in sheepmeat. Lambs from low and high intramuscular fat sires were allocated to one of four finishing feeds-perennial ryegrass (Lolium perenne), lucerne, and two brassica forages-for a 6 week period. Grilled loins (Longissimus thoracis et lumborum) were subjected to chemical and sensory analysis by a trained panel and also evaluated by non-Chinese and Chinese background Australian consumers. Consumer liking was similar for both groups, and liking was highest for the brassica- and lucerne-finished lamb, especially from high intramuscular fat sires. No evidence of a distinctive lucerne- or brassica-induced flavor taint was measured by the trained panel or gas chromatography-mass spectrometry-olfactometry. The diets influenced the composition of lipids and branched-chain fatty acids in the subcutaneous fat, and the concentration of total branched-chain fatty acids was positively correlated with flavor and overall liking. Significantly higher levels of key aroma volatiles were measured in the higher fat samples.

Sensory and Flavor Chemistry Characteristics of Australian Beef: Influence of Intramuscular Fat, Feed, and Breed.

The sensory attributes and flavor chemistry of grilled beef striploins (M. longissimus lumborum, n = 42) varying widely in marbling from commercial production types typical for Southern Australia were extensively characterized. Striploins from Angus grass-fed yearlings (5.2-9.9% intramuscular fat), Angus grain-finished steers (10.2-14.9%), and Wagyu grass-fed heifers (7.8-17.5%) were evaluated. Inherent differences between samples from grass- and grain-fed Angus cattle were minimal when the intramuscular fat content was above ∼5%. After adjusting for intramuscular fat, Wagyu samples had more intense flavor and higher tenderness and juiciness compared to Angus grass-fed samples. Grilled beef flavor, dairy fat, and sweetness increased with the marbling level, and sourness and astringency decreased. Tenderness and juiciness increased with the marbling level and were correlated with Warner-Bratzler peak force measurements. Trained panel sensory differences in flavor corresponded with increases in aroma volatiles and changes in nonvolatile flavor compounds. Unsaturated fatty acids with potential health benefits (vaccenic, oleic, and rumenic acids) increased with the level of marbling.

Lipid oxidation volatiles absent in milk after selected ultrasound processing.

Ultrasonic processing can suit a number of potential applications in the dairy industry. However, the impact of ultrasound treatment on milk stability during storage has not been fully explored under wider ranges of frequencies, specific energies and temperature applications. The effect of ultrasonication on lipid oxidation was investigated in various types of milk. Four batches of raw milk (up to 2L) were sonicated at various frequencies (20, 400, 1000, 1600 and 2000kHz), using different temperatures (4, 20, 45 and 63°C), sonication times and ultrasound energy inputs up to 409kJ/kg. Pasteurized skim milk was also sonicated at low and high frequency for comparison. In selected experiments, non-sonicated and sonicated samples were stored at 4°C and were drawn periodically up to 14days for SPME-GCMS analysis. The cavitational yield, characterized in all systems in water, was highest between 400kHz and 1000kHz. Volatile compounds from milk lipid oxidation were detected and exceeded their odor threshold values at 400kHz and 1000kHz at specific energies greater than 271kJ/kg in raw milk. However, no oxidative volatile compounds were detected below 230kJ/kg in batch systems at the tested frequencies under refrigerated conditions. Skim milk showed a lower energy threshold for oxidative volatile formation. The same oxidative volatiles were detected after various passes of milk through a 0.3L flow cell enclosing a 20kHz horn and operating above 90kJ/kg. This study showed that lipid oxidation in milk can be controlled by decreasing the sonication time and the temperature in the system depending on the fat content in the sample among other factors.

Stabilization of fish oil-in-water emulsions with oleosin extracted from canola meal.

International dietary guidelines advocate replacement of saturated and trans fat in food with unsaturated oils. Also, there is growing interest in incorporating highly unsaturated omega-3 oils in to food products due to beneficial health effects. A major obstacle to incorporating highly unsaturated oils in to food products is the extreme susceptibility to oxidative deterioration. Oil bodies were prepared from tuna oil, oleosin, and phospholipid mimicking natural oil bodies within oilseed. Oleosin was extracted from canola (Brassica napus) meal by solubilization in aqueous sodium hydroxide (pH 12) and subsequent precipitation at its isoelectric point of pH 6.5. The tuna oil artificial oil bodies (AOBs) readily dispersed in water to produce oil-in-water (o/w) emulsions, which did not coalesce on storage and were amenable to pasteurization using standard conditions. Accelerated oxidation studies showed that these AOB emulsions were substantially more resistant to lipid oxidation than o/w emulsions prepared from tuna oil using Tween40, sodium caseinate, and commercial canola protein isolate, respectively. There is potential to use commercial canola meal, which is cheap and abundant, as a natural source of oleosin for the preparation of physically and oxidatively stable food emulsions containing highly unsaturated oils.

Molecular size fractions of bay leaf (Laurus nobilis) exhibit differentiated regulation of colorectal cancer cell growth in vitro.

Numerous in vitro studies using solvent or aqueous extracts of raw dietary plant material have demonstrated modulation of colon cancer cell growth and apoptosis and effects on immune and nonimmune pathways of inflammation. We have developed a generic, 3-staged food-compatible process involving heating for conversion of dietary plants into food ingredients and report results on potential colon cancer-regulating properties of processed forms of Bay leaf (Laurus nobilis). In vitro studies demonstrated inhibition of cancer cell growth by processed Bay leaf products in HT-29, HCT-116, Caco-2, and SW-480 human cancer cell lines, which were accompanied by variable levels of elevated apoptosis. Bay leaf also exerted moderate inhibition of cycloxygenase 2 and 5 lipoxygenase enzymatic activity. In addition, these extracts significantly downregulated interferon-γ production in T helper Type 1-stimulated whole blood from healthy donors. Furthermore, size fractionation of the extracts revealed that antiproliferative and proapoptotic activities were associated with low mass (primarily polyphenolics and essential oils) and high mass (primarily proteins including polyphenol oxidase) chemical classes, respectively. Bay leaf exerted in vitro bioactivity that might be relevant to protecting against early events in sporadic colorectal cancer, with potential for further optimization of bioactivity by size-based fractionation.

Sheepmeat flavor and the effect of different feeding systems: a review.

Lamb has a unique flavor, distinct from other popular red meats. Although flavor underpins lamb's popularity, it can also be an impediment to consumer acceptance. Lack of familiarity with sheepmeat flavor itself can be a barrier for some consumers, and undesirable feed-induced flavors may also compromise acceptability. Against the backdrop of climate uncertainty and unpredictable rainfall patterns, sheep producers are turning to alternatives to traditional grazing pasture systems. Historically, pasture has been the predominant feed system for lamb production in Australia and around the world. It is for this reason that there has been a focus on "pastoral" flavor in sheep meat. Pasture-associated flavors may be accepted as "normal" by consumers accustomed to meat from pasture-fed sheep; however, these flavors may be unfamiliar to consumers of meat produced from grain-fed and other feed systems. Over the past few decades, studies examining the impacts of different feeds on lamb meat quality have yielded variable consumer responses ranging from "no effect" to "unacceptable", illustrating the diverse and sometimes inconsistent impacts of different forages on sheepmeat flavor. Despite considerable research, there is no consensus on which volatiles are essential for desirable lamb aroma and how they differ compared to other red meats, for example, beef. In contrast, comparatively little work has focused specifically on the nonvolatile taste components of lamb flavor. Diet also affects the amount of intramuscular fat and its fatty acid composition in the meat, which has a direct effect on meat juiciness and texture as well as flavor, and its release during eating. The effect of diet is far from simple and much still needs to be learned. An integrated approach that encompasses all input variables is required to better understand the impact of the feed and related systems on sheepmeat flavor. This review brings together recent research findings and proposes some novel approaches to gain insights into the relationship between animal diet, genetics, and sheepmeat quality.

A family of doctors over 250 years: innovation and controversy.

A family of Watkins doctors originating in the Northamptonshire town of Towcester included 13 doctors in seven generations during 250 years. In each generation there were between one and four doctors. Three doctors involved themselves actively in innovative yet controversial practises, described in their own writings and publications. Timothy Watkins' (1755-1834) own handwritten lecture notes describe the problems affecting an 18th-century man-midwife, while his accounts book provides insights into his lifestyle. The concept of the waterborne spread of cholera during the 1854 epidemic in Towcester is described by Robert Webb Watkins (1822-1901) during the same year as the observations made by John Snow (1813-58). John Webb Watkins (1833-1903) in his MD thesis (1856) describes his use of chloroform in labour in Towcester during the early 1850s, followed by self-experimentation with chloroform administered to him between 40 and 50 times by Sir James Young Simpson (1811-70) in Edinburgh. Descriptions of the two 19th-century general practitioners offer insights into the exemplary extent of their civic involvement in all walks of local community life, and of their family ties.

A hybrid genetic algorithm for estimating the equilibrium potential of an ion-selective electrode.

Non-linear equations can be used to model the measured potential of ion-selective electrodes (ISEs) as a function of time. This can be done by using non-linear least squares regression to fit parameters of non-linear equations to an ISE response curve. In iterative non-linear least squares regression (which can be considered as local optimisers), the determination of starting parameter estimates that yield convergence to the global optimum can be difficult. Starting values away from the global optimum can lead to either abortive divergence or convergence to a local optimum. To address this issue, a global optimisation technique was used to find initial parameter estimates near the global optimum for subsequent further refinement to the absolute optimum. A genetic algorithm has been applied to two non-linear equations relating the measured potential from selected ISEs to time. The parameter estimates found from the genetic algorithm were used as starting values for non-linear least squares regression, and subsequent refinement to the absolute optimum. This approach was successfully used for both expressions with measured data from three different ISEs; namely, calcium, chloride and lead ISEs.

Application of zNosetrade mark for the analysis of selected grape aroma compounds.

A novel and portable gas chromatograph (GC, zNosetrade mark) has been evaluated for the measurement in grape berries of selected six-carbon compounds; namely, hexanal, cis-2-hexen-1-ol, cis-3-hexen-1-ol and trans-2-hexenal. The zNosetrade mark is a handheld GC which uses purge and trap for concentration, and has a surface acoustic wave (SAW) sensor as a detector. Operation of the zNosetrade mark using direct aspiration of the sample failed to detect the compounds at the reported odour threshold values. Pre-concentration by Tenax((R)) trapping and solid-phase microextraction (SPME) were investigated to improve the zNosetrade mark sensitivity. Use of a Tenax((R)) pre-trap with the zNosetrade mark allowed detection of the compounds at concentration levels in the order of their threshold values. Excessive bleed from the SPME fibre prevented the use of SPME with zNosetrade mark.