Application of cellulose- and chitosan-based edible coatings for quality and safety of deep-fried foods.

Excessive oil uptake and formation of carcinogens, such as acrylamide (AA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs), during deep-frying are a potential threat for food quality and safety. Cellulose- and chitosan-based edible coatings have been widely applied to deep-fried foods for reduction of oil uptake because of their barrier property to limit oil ingress, and their apparent inhibition of AA formation. Cellulose- and chitosan-based edible coatings have low negative impacts on sensory attributes of fried foods and are low cost, nontoxic, and nonallergenic. They also show great potential for reducing HCAs and PAHs in fried foods. The incorporation of nanoparticles improves mechanical and barrier properties of cellulose and chitosan coatings, which may also contribute to reducing carcinogens derived from deep-frying. Considering the potential for positive health outcomes, cellulose- and chitosan-based edible coatings could be a valuable method for the food industry to improve the quality and safety of deep-fried foods.

Cereal grain-based functional beverages: from cereal grain bioactive phytochemicals to beverage processing technologies, health benefits and product features.

Increased consumer awareness of health and wellness has promoted a high demand for foods and beverages with functional and therapeutic properties. Cereals, apart from being important staple crops and primary sources of energy and nutrition, are replete with bioactive phytochemicals with health properties. Cereal grains contain a diverse range of bioactive phytochemicals including phenolic compounds, dietary fibers, carotenoids, tocols, phytosterols, γ-oryzanol, and phytic acid and therefore have great potential for processing into functional beverages. Although there are a variety of cereal grain-based beverages produced world-wide, very little scientific and technological attention has been paid to them. In this review, we have discussed cereal grain-based functional beverages based on 3 main categories: cereal grain-based milk alternatives, roasted cereal grain teas, fermented nonalcoholic cereal grain beverages. The processing techniques, health properties and product features of these beverages are elaborated, and the challenges and future perspectives are proposed. As the food market becomes increasingly diverse, cereal grain-based beverages could be a promising new category of health functional beverages in our daily life.

Reduction strategies for polycyclic aromatic hydrocarbons in processed foods.

Polycyclic aromatic hydrocarbons (PAHs) are a large group of carcinogenic compounds. PAHs are ubiquitous in the environment and food, thus human beings may be exposed to PAHs through ingestion (water and food), inhalation (air and smoking), and skin contact in daily life. Dietary intake is the major source of exposure to PAHs in humans. Significant and harmful levels of PAHs can be generated during food processing and cooking. Although the formation of PAHs during processing is almost unavoidable, the levels can be diminished with reduction strategies. This review aims to provide comprehensive insights into the mechanisms underlying the formation of PAHs and factors influencing their formation in processed foods. The strategy for the reduction of PAHs including change in ingredients (i.e., reducing fat content), pretreatment conditions (i.e., reducing the pH), processing methods and parameters (i.e., reducing processing temperature and time), and packaging and storage conditions, are discussed. Potential novel strategies for PAH reduction are also identified and the feasibility is evaluated.

LC-ESI-QTOF-MS/MS Characterization of Seaweed Phenolics and Their Antioxidant Potential.

Seaweed is an important food widely consumed in Asian countries. Seaweed has a diverse array of bioactive compounds, including dietary fiber, carbohydrate, protein, fatty acid, minerals and polyphenols, which contribute to the health benefits and commercial value of seaweed. Nevertheless, detailed information on polyphenol content in seaweeds is still limited. Therefore, the present work aimed to investigate the phenolic compounds present in eight seaweeds [Chlorophyta (green), Ulva sp., Caulerpa sp. and Codium sp.; Rhodophyta (red), Dasya sp., Grateloupia sp. and Centroceras sp.; Ochrophyta (brown), Ecklonia sp., Sargassum sp.], using liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS). The total phenolic content (TPC), total flavonoid content (TFC) and total tannin content (TTC) were determined. The antioxidant potential of seaweed was assessed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, a 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assay and a ferric reducing antioxidant power (FRAP) assay. Brown seaweed species showed the highest total polyphenol content, which correlated with the highest antioxidant potential. The LC-ESI-QTOF-MS/MS tentatively identified a total of 54 phenolic compounds present in the eight seaweeds. The largest number of phenolic compounds were present in Centroceras sp. followed by Ecklonia sp. and Caulerpa sp. Using high-performance liquid chromatography-photodiode array (HPLC-PDA) quantification, the most abundant phenolic compound was p-hydroxybenzoic acid, present in Ulva sp. at 846.083 ± 0.02 µg/g fresh weight. The results obtained indicate the importance of seaweed as a promising source of polyphenols with antioxidant properties, consistent with the health potential of seaweed in food, pharmaceutical and nutraceutical applications.

Impacts of heat stress on meat quality and strategies for amelioration: a review.

During the summer, high ambient temperature and humidity cause economic loss to the global livestock industry via reduced livestock productivity and increased mortality. The problem of heat stress (HS) is likely to be exacerbated by global warming and climate change. Recent research has shown that HS not only leads to physiological and metabolic perturbations in live animals but can also affect carcass and meat quality characteristics plausibly by altering the rate and extent of postmortem muscle glycolysis and resultant pH. However, these impacts of HS are not consistent across species. Higher incidence of pale soft and exudative (PSE) meat has been reported in poultry. On the contrary, higher incidence of high ultimate pH and dark firm and dry (DFD) meat or no impacts of HS have been reported in sheep and cattle. With the limited data on HS impacts on meat quality of ruminants, it is difficult to explain the exact mechanisms driving these variable impacts. However, it is hypothesized that the severity and duration of HS may lead to variable impacts due to lack of opportunity to adapdate to acute heat exposure. Longer HS exposure may allow ruminants to adapdate to heat and may not record any negative impacts on meat quality. This paper reviews the recent research on impacts of HS on meat quality characteristics and identify the key areas of further research required to better understand these negative impacts to develop strategies for amelioration. In addition, some mitigation strategies of HS have also been discussed which include both managemental and nutritional interventions.

Meat color is determined not only by chromatic heme pigments but also by the physical structure and achromatic light scattering properties of the muscle.

Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.

3-Deoxyanthocyanidin Colorant: Nature, Health, Synthesis, and Food Applications.

3-Deoxyanthocyanidins are a rare type of anthocyanins that are present in mosses, ferns, and some flowering plants. They are water-soluble pigments and impart orange-red and blue-violet color to plants and play a role as phytoalexins against microbial infection and environmental stress. In contrast to anthocyanins, the lack of a hydroxyl group at the C-3 position confers unique chemical and biochemical properties. They are potent natural antioxidants with a number of potential health benefits including cancer prevention. 3-Deoxyanthocyanidin pigments have attracted much attention in the food industry as natural food colorants, mainly due to their higher stability during processing and handling conditions compared with anthocyanins. They are also photochromic compounds capable of causing a change in "perceived" color, when exposed to UV light, which can be used to design novel foods and beverages. Due to their interesting properties and potential industrial applications, great efforts have been made to synthesize these compounds. For biosynthesis, researchers have discovered the 3-deoxyanthocyanidin biosynthetic pathway and their biosynthetic genes. For chemical synthesis, advances have been made to synthesize the compounds in a simpler and more efficient way as well as looking for its novel derivative with enhanced coloration properties. This review summarizes the developments in the research on 3-deoxyanthocyanidin as a colorant, from natural sources to chemical syntheses and from health benefits to applications and future prospects, providing comprehensive insights into this group of interesting compounds.

Sorghum Grain: From Genotype, Nutrition, and Phenolic Profile to Its Health Benefits and Food Applications.

Globally, sorghum is one of the most important but least utilized staple crops. Sorghum grain is a rich source of nutrients and health-beneficial phenolic compounds. The phenolic profile of sorghum is exceptionally unique and more abundant and diverse than other common cereal grains. The phenolic compounds in sorghum are mainly composed of phenolic acids, 3-deoxyanthocyanidins, and condensed tannins. Studies have shown that sorghum phenolic compounds have potent antioxidant activity in vitro, and consumption of sorghum whole grain may improve gut health and reduce the risks of chronic diseases. Recently, sorghum grain has been used to develop functional foods and beverages, and as an ingredient incorporated into other foods. Moreover, the phenolic compounds, 3-deoxyanthocyanidins, and condensed tannins can be isolated and used as promising natural multifunctional additives in broad food applications. The objective of this review is to provide a comprehensive understanding of nutrition and phenolic compounds derived from sorghum and their related health effects, and demonstrate the potential for incorporation of sorghum in food systems as a functional component and food additive to improve food quality, safety, and health functions.

Machine Vision Requires Fewer Repeat Measurements than Colorimeters for Precise Seafood Colour Measurement.

The colour of seafood flesh is often not homogenous, hence measurement of colour requires repeat measurements to obtain a representative average. The aim of this study was to determine the optimal number of repeat colour measurements required for three different devices [machine vision (digital image using camera, and computer processing); Nix Pro; Minolta CR400 colorimeter] when measuring three species of seafood (Atlantic salmon, Salmo salar, n = 8; rockling, Genypterus tigerinus, n = 8; banana prawns, Penaeus merguiensis, n = 105) for raw and cooked samples. Two methods of analysis for number of repeat measurements required were compared. Method 1 was based on minimising the standard error of the mean and Method 2 was based on minimising the difference in colour over repeat measurements. Across species, using Method 1, machine vision required an average of four repeat measurements, whereas Nix Pro and Minolta required 13 and 12, respectively. For Method 2, machine vision required an average of one repeat measurement compared to nine for Nix Pro and Minolta. Machine vision required fewer repeat measurements due to its lower residual variance: 0.51 compared to 3.2 and 2.5 for Nix Pro and Minolta, respectively. In conclusion, machine vision requires fewer repeat measurements than colorimeters to precisely measure the colour of salmon, prawns, and rockling.

Impact of cooking temperature on pork longissimus, and muscle fibre type, on quality traits and protein denaturation of four pork muscles.

Variations in pork quality impact consumer acceptance, and fibre type differences between muscles contribute to this variation. The aim was to investigate the influence of variations in muscle fibre types and protein denaturation peaks across four pork muscles and the influence of ageing and cooking temperature on longissimus quality traits. The longissimus, masseter, cutaneous trunci, and psoas major from 13 carcases were removed 1-day postmortem and subjected to 0- or 14-days ageing (d0, d14). Quality traits, protein denaturation peak temperature (DSC), fibre diameter and fibre type proportions were measured. Cook loss for longissimus was similar on d0 and d14, but was higher on d14 for masseter, cutaneous trunci, and psoas major. Warner-Bratzler shear force was highest, and ultimate pH was lowest, for longissimus, and similar among cutaneous trunci, masseter, and psoas major. Masseter had lowest L* and highest a* and longissimus and cutaneous trunci had highest L* and lowest a*. The DSC temperature peaks for longissimus occurred at lower temperatures relative to the other muscles. Fibre diameter was largest for type-IIb fibres relative to type-IIa and type-I. Longissimus and cutaneous trunci had predominantly type-IIb glycolytic (71%, 51% respectively), masseter had predominantly type-IIa intermediate (50%) and psoas major had predominantly type-I oxidative (48%) fibres. The glycolytic longissimus had the lowest DSC temperature peaks and the lowest quality meat. Masseter had the highest proportion of type-I fibres but was generally similar in quality traits to psoas major, and also similar to cutaneous trunci which had more glycolytic fibres than masseter.

Targeted-metabolomic and untargeted-proteomic approaches reveal the effects of muscle fibre type and postmortem ageing on taste-active compounds in beef.

The taste of beef is caused by taste-active compounds detected in the mouth during mastication. We hypothesised that the concentration of taste-active compounds in beef is influenced by muscle-fibre-type and postmortem ageing. To test this, and unravel the underlying mechanisms, we investigated the taste-active compounds, and proteomic profiles, in beef masseter [oxidative muscle, all type I fibres) and cutaneous trunci (glycolytic muscle, mostly type II fibres) before and after 14-days postmortem ageing. Our results showed that nucleotides were initially higher and degraded slower in cutaneous trunci (P < 0.05 for both), which could be explained by the profile of nucleotide metabolism enzymes. In contrast, free amino acids were initially higher and increased more in masseter compared to cutaneous trunci (P < 0.05 for all), which might be explained by the profile and activity of proteases in these two muscles. Our results indicate the taste of beef is affected by the muscle-fibre-type and postmortem ageing.

Rinse and chill®, frozen storage and retail packaging influence the quality of lamb loins.

This study evaluated effects of Rinse&Chill® vs. control, storage condition (fresh, frozen-thawed) and retail packaging (high oxygen modified atmosphere packaging, vacuum skin packaging) on quality of lamb loins. Thirty-two lambs were slaughtered, and carcasses were allocated to Rinse&Chill® or control (n = 16 for each). Loins were aged for seven-days (fresh), and then allocated to fresh or freezing-thawing (frozen-thawed). After storage completion loins were cut into steaks then packaged in high oxygen modified atmosphere packaging (HiOxMAP) or vacuum skin packaging (VSP) and into 8-days simulated retail display. Rinse&Chill® samples had lower heme protein content and lipid oxidation (p < 0.05 for both) compared to control samples. In frozen-thawed lamb samples, VSP resulted in lower lipid oxidation, higher red values (a*), and lower Warner-Bratzler shear force compared to those in HiOxMAP (p < 0.05 for all). This study showed that Rinse&Chill® reduced lipid oxidation in lamb loins, and VSP can be used to improve the quality of frozen-thawed lamb in retail.

Muscle fibre type composition influences the formation of odour-active volatiles in beef.

Flavour is a key driver of consumer liking, and odour-active volatiles formed in cooking are important contributors to the flavour of cooked beef. We hypothesised that the formation of odour-active volatiles in beef are influenced by the contents of type I oxidative and type II glycolytic muscle fibres. To test our hypothesis, we combined ground masseter (type I) and cutaneous trunci (type II) into beef patties, cooked them, then their volatile profiles were analysed using gas chromatography-mass spectrometry. Antioxidant capacity, pH, total heme protein, free iron, and fatty acid composition of these patties were also measured to investigate their relationship to volatile formation. Our study showed that beef composed of more type I fibres had higher 3-methylbutanal and 3-hydroxy-2-butanone, but less lipid-derived volatiles, and this could be partially attributed to the higher antioxidant capacity, pH, and total heme protein content in type I fibres. The results of our study indicate that fibre-type composition plays an important role in volatile formation and hence flavour of beef.

Bushfire exposure is associated with increased pH and dark-cutting in beef longissimus thoracis at grading.

To investigate if bushfire exposure is associated with increased loin pH, this study analysed temporal and geospatial data on fire incidence in South-Eastern Australia together with beef carcase quality and production records for fire affected animals (n = 451,299). Two outcomes were modelled: 1) loin pH at time of grading, and 2) the incidence of "high pH" defects (pH > 5.70). For both models, decreasing "time since closest fire" and "distance of property from closest fire" were associated with increasing loin pH and increased incidence of high pH carcases(p < 0.05 for all); interactions for "distance from the closest fire" with feed type (grain vs grass) and "days of fire exposure" with HGP (hormonal growth promotant) treatment (yes vs no) (p < 0.05 for both) indicate high pH outcomes were exacerbated in grass-fed and HGP treated cattle. It is concluded that exposure to bushfire is associated with increasing pH but the extent and magnitude of these increases are modulated by production factors.

Understanding consumer liking of beef patties with different firmness among younger and older adults using FaceReader™ and biometrics.

Sensorial perceptions change as people age and biometrics analysis can be used to explore the unconscious consumer responses. Investigation was conducted of effects of consumer age (younger, 22-52 years; older, 60-76 years) on facial expression response (FER) during consumption of beef patties with varying firmness (soft, medium, hard) and taste (±plum sauce). Video images were collected and FERs analysed using FaceReader™. Younger people exhibited higher intensity for happy/sad/scared and lower intensity for neutral/disgusted, relative to older people. Interactions between age and texture/sauce showed little FER variation in older people, whereas younger people showed considerable FER variation. Younger people, but not older people, had lowest intensity of happy FER and highest intensity of angry FER for the hard patty. Sauce addition resulted in higher intensity of happy/contempt in younger consumers, but not older consumers. FER collected using FaceReader™ was successfully used to differentiate between the unconscious responses of younger and older consumers.

Meta-Regression Analysis of Relationships between Fibre Type and Meat Quality in Beef and Pork-Focus on Pork.

This meta-regression analysis was conducted to identify the relationship between fibretype cross-sectional area (CSA) and frequency (%) and meat quality traits, especially tenderness (sensory and Warner-Bratzler Shear Force, WBSF). Literature searches were conducted using specific keywords which resulted in 32 peer-reviewed manuscripts that contained averages and correlation coefficients for fibre type (frequency and CSA) and quality traits of longissimus muscle for beef and pork (7 and 25 studies respectively). Correlations were analysed in meta-regression using R-Studio and linear regression was also conducted. For the combined beef and pork analysis, only pH, WBSF, and drip loss were associated with fibre type frequency and CSA (p < 0.05 for all). Limiting the analysis to pork, the key results were frequency of type I fibres were associated with decreased drip loss, increased cook loss, decreased lightness (L*) and increased sensory tenderness whereas frequency of type IIb fibres were associated with increased drip loss (p < 0.05 for all). In addition, the CSA of type I and IIb fibres was associated with colour traits lightness and redness (p < 0.05 for all). Future research should focus on fibre type across breeds and muscles to further understand the impacts of fibre type frequency and CSA on quality.

Collagen characteristics affect the texture of pork Longissimus and Biceps femoris.

Connective tissue is considered to influence the toughness of pork, but most studies on connective tissue focus on the loin muscle. Cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis (hardness, springiness, chewiness, resilience, and cohesiveness), total and insoluble collagen content, the percentage of type III collagen relative to the total of type I and III collagen, proteoglycan content and intramuscular fat (IMF) content were measured for pork Biceps femoris (BF) and Longissimus thoracis et lumborum (LTL) and Pearson's correlation was performed. The results showed that BF had higher WBSF, resilience, total, and insoluble collagen content than LTL (P < 0.05). When considering both muscles, total and insoluble collagen content were positively correlated (P < 0.05) with WBSF (r = 0.47 and 0.49, respectively), hardness (r = 0.49 and 0.50, respectively), cohesiveness (r = 0.50 and 0.50, respectively), chewiness (r = 0.58 and 0.59, respectively) and resilience (r = 0.63 and 0.63, respectively). The percentage of type III collagen content was negatively correlated (P < 0.05) with WBSF (r = -0.68) and hardness (r = -0.58). Collagen content was correlated (P < 0.05) with WBSF (r = 0.75) and hardness (r = 0.61) in LTL and with cohesiveness (r = 0.74) and resilience (r = 0.63) in BF. Collagen characteristics differ between muscles and contribute to pork texture in both LTL and BF.

Consumer Characterization of Wet- and Dry-Aged Mutton Flavor Profile Using Check-All-That-Apply.

The aim of this study was to assess if consumers could characterize wet- and dry-aged mutton flavor profiles using CATA (check-all-that-apply). A flavor lexicon was developed for mutton, and consumers assessed wet- and dry-aged mutton patties against this lexicon using CATA methodology. Results indicate that consumers most often associated caramel and roasted flavors with dry-aged patties, and "sheepy" and metallic flavors with wet-aged patties. Volatile analysis supported the consumer characterization as there were more Maillard reaction products, including pyrazines, which are associated with roasted and cooked flavors, found in the dry-aged patty volatile profile. More 1-octen-3-one, which is associated with metallic flavors, was found in the wet-aged patty volatile profile. These results provide validation that the lexicon utilized in this study (i) is suitable for the characterization of mutton flavor and (ii) will have applications for future investigations into the flavor components driving consumer liking for mutton.

Meta-analysis of the relationship between collagen characteristics and meat tenderness.

Meta-analysis methods were used to investigate the effects of collagen content, solubility and pyridinoline cross-link content on Warner-Bratzler shear force (WBSF) and sensory tenderness in major meat species. Data was collected from the literature on pork, beef and lamb and analyzed independently for each species. The beef data was categorized into subgroups according to muscle (loin and other muscle) and age (young, <18 months and old, ≥18 months). The results showed that in beef, collagen content and pyridinoline cross-link content were positively correlated with WBSF and negatively with sensory tenderness, while collagen solubility was negatively correlated with WBSF. The correlation coefficients were greater in other beef muscles than loin. Significant correlations between collagen content and tenderness attributes were observed in old beef animals. However, non-significant relationships and large variations were found in pork and lamb. More studies with various muscles and ages are required for an in-depth understanding of the relationship between collagen characteristics and meat tenderness.

The texture and mastication properties of sheep biceps femoris from different finishing feeds and retail packaging methods.

This study investigated the relationship among meat texture (Warner-Bratzler shear force [WBSF] and texture profile analysis [TPA]), water-holding capacity, and subsequent mastication of meat from sheep fed different diets and maintained under different packaging methods. Biceps femoris from 24 Merino sheep fed a standard pelleted diet containing grain and cereal hay or pelleted diets supplemented with either 8% camelina meal or 15% camelina forage hay was packaged in high-oxygen modified atmosphere packaging (hiOxMAP) or vacuum skin packaging (VSP). WBSF, TPA, and water-holding capacity (purge loss and cooking loss) were measured. Twelve volunteers were recruited to chew the cooked meat samples before expectorating the bolus at their natural swallowing point. Meat stored in hiOxMAP had greater purge loss, Warner-Bratzler peak force, hardness, and chewiness compared to meat packed in VSP. Mastication testing revealed that chewing frequency increased with VSP meat compared to hiOxMAP meat. Feed type had little effect on meat texture parameters; however, sheep meat on the standard pelleted diet required a greater number of chews than sheep finished on diet supplemented with camelina meal. Increased toughness in cooked meat due to feed type or packaging methods resulted in greater chewing effort, but this did not affect meat bolus properties at the natural swallowing point.