Assessment of Biotechnologically Important Filamentous Fungal Biomass by Fourier Transform Raman Spectroscopy.

Oleaginous filamentous fungi can accumulate large amount of cellular lipids and biopolymers and pigments and potentially serve as a major source of biochemicals for food, feed, chemical, pharmaceutical, and transport industries. We assessed suitability of Fourier transform (FT) Raman spectroscopy for screening and process monitoring of filamentous fungi in biotechnology. Six Mucoromycota strains were cultivated in microbioreactors under six growth conditions (three phosphate concentrations in the presence and absence of calcium). FT-Raman and FT-infrared (FTIR) spectroscopic data was assessed in respect to reference analyses of lipids, phosphorus, and carotenoids by using principal component analysis (PCA), multiblock or consensus PCA, partial least square regression (PLSR), and analysis of spectral variation due to different design factors by an ANOVA model. All main chemical biomass constituents were detected by FT-Raman spectroscopy, including lipids, proteins, cell wall carbohydrates, and polyphosphates, and carotenoids. FT-Raman spectra clearly show the effect of growth conditions on fungal biomass. PLSR models with high coefficients of determination (0.83-0.94) and low error (approximately 8%) for quantitative determination of total lipids, phosphates, and carotenoids were established. FT-Raman spectroscopy showed great potential for chemical analysis of biomass of oleaginous filamentous fungi. The study demonstrates that FT-Raman and FTIR spectroscopies provide complementary information on main fungal biomass constituents.

Application of winter mushroom powder as an alternative to phosphates in emulsion-type sausages.

This research evaluated the utilization of winter mushrooms as a replacement for phosphate in emulsion-type sausages. Winter mushroom powder (WMP) was added to the sausages at 0, 0.5, 1.0, 1.5, and 2.0% (w/w), and phosphate was added at 0.3% as a positive control. The WMP additions above 1.0% increased the pH of meat batter and efficiently inhibited the exudation of fat from the sausages (p < 0.05). Lipid oxidation of sausages was inhibited by the addition of WMP (p < 0.05). On the other hand, the addition of phosphate and WMP provided different instrumental texture properties. However, no adverse effects were observed with respect to the color and sensory properties of the sausages containing WMP, except for that containing 2.0% WMP. Therefore, this research indicates that WMP can effectively replace phosphate in meat products, and that the most effective addition level may be 1.0% WMP.

Effect of pear apple and date fibres incorporation on the physico-chemical, sensory, nutritional characteristics and the acceptability of cereal bars.

Cereal bars are nutritious food composed of several ingredients including dry raw and agglutinative ingredients. The objective of this study was to evaluate the effect of pear apple and date fibres, from cooked fruit co-product, addition on the physico-chemical textural and sensory properties of cereal bars. First, five formulations containing an amount of 10% of co-products and commercial fibre, used as a reference, were elaborated and their physico-chemical composition was determined. Second, to determine the acceptability of consumer, apple fibre co-products were added (6, 10 and 14%). Products were evaluated for their texture using a texturometer and sensory characteristics using an acceptance test. Results showed that physico-chemical composition of cereal bars elaborated with co-products was slightly different compared to those elaborated with commercial fibre. All bars have low water activity levels (∼0.470) and interesting energy (300 kcal/100 g bar). External appearance revealed a darker colour (L*:∼42/a*:∼8/b*:∼20). There were no significant differences (P > 0.05) in texture values (hardness: 40.8 N; cohesiveness: 0.34; springiness: 0.60; chewiness: 8.30 N) between cereal bars prepared with pear co-product and wheat bran. Acceptance test confirms the formulation used for cereals bars and showed that incorporation of 10% of co-product produced cereal bars with the highest acceptability. Sensory characteristics revealed that appearance is the limiting factor for consumer acceptability, essentially for cereal bars containing pear co-product. Apple, pear and date co-products could be used successfully as a food ingredient to develop new formulations of cereal bars.

Quality characteristics of sauerkraut fermented by using a Lactobacillus paracasei starter culture grown in tofu whey.

The quality parameters of sauerkraut fermented using Lactobacillus paracasei in terms of its lactic acid bacteria count, texture, colour and biochemical properties were studied. As a starter culture L. paracasei grown in tofu whey was used for sauerkraut fermentation. The experiments were planned using central composite rotatable design of response surface methodology for input variables - culture volume (ml), fermentation time (days) and salt concentration (g/100 g). The linear and interactive effect of variables on responses was understood by statistically significant (p < 0.01) second-order models. Amongst all the input variables culture volume was found to have an overwhelming effect over all the responses. There was a significant (p < 0.01) increase in the lactic acid bacteria count of finished product; it was less hard but there was a departure in colour from the traditional product. The optimized condition for sauerkraut fermentation in terms of culture volume (ml), fermentation time (day) and salt concentration (g/100 g) was 30 ml, 28 days and 1 g/100 g, respectively. It was also observed that phenolics content was better in starter culture sauerkraut over the one traditionally prepared.

Composition of legume soaking water and emulsifying properties in gluten-free bread.

Soaking of legumes results in the loss of macronutrients, micronutrients and phytochemicals. Fibre, protein and phytochemicals found in legumes exert emulsifying activity that may improve the structure and texture of gluten-free bread. The legume soaking water of haricot beans, garbanzo chickpeas, whole green lentils, split yellow peas and yellow soybeans were tested in this study for functional properties and use as food ingredients. Composition, physicochemical properties and effect on the quality of gluten-free bread were determined for each legume soaking water. Haricot beans and split yellow peas released the highest amount of solids in the legume soaking water: 1.89 and 2.38 g/100 g, respectively. Insoluble fibre was the main constituent of haricot beans legume soaking water, while water-soluble carbohydrates and protein were the major fraction of split yellow peas. High quantities of phenolics (∼400 µg/g) and saponins (∼3 mg/g) were found in the legume soaking water of haricot beans, whole green lentils and split yellow peas. High emulsifying activity (46 and 50%) was found for the legume soaking water of garbanzo chickpeas and split yellow peas, probably due to their protein content and high ratio of water-soluble carbohydrates to dry matter. Such activity resulted in softer texture of the gluten-free bread. A homogeneous structure of crumb pores was found for split yellow peas, opposing that of whole green lentils. A balance between the contents of yeast nutrients and antinutrients was the likely basis of the different appearances.

Effect of different irradiation dose treatment on the lipid oxidation, instrumental color and volatiles of fresh pork and their changes during storage.

This study mainly investigated the effect of different doses irradiation (0, 3, 5 or 7kGy) on the quality changes of pork during 4°C storage by determining the irradiation off-odor intensity, thiobarbituric acid reactive substances (TBARs), fatty acid composition, volatiles and color of the samples during whole storage. The results showed that ≥7kGy irradiation could make the samples produce obvious irradiation off-odor. However, after 7days storage irradiation off-odor was reduced. Lipid oxidation was also promoted by irradiation. Benzyl methyl sulfide was produced newly and significantly increased (P<0.05) by irradiation. Fatty acids in pork samples decreased significantly with irradiation dose increase within the range of <7kGy, but significantly increased (P<0.05) in samples of 7kGy. Irradiation significantly increased the a* values regardless of storage time but had little effects on b* and L* values, and the increase of a* values was dose-dependent.

Fast detection of leaf pigments and isoprenoids for ecophysiological studies, plant phenotyping and validating remote-sensing of vegetation.

Rapid developments in remote-sensing of vegetation and high-throughput precision plant phenotyping promise a range of real-life applications using leaf optical properties for non-destructive assessment of plant performance. Use of leaf optical properties for assessing plant performance requires the ability to use photosynthetic pigments as proxies for physiological properties and the ability to detect these pigments fast, reliably and at low cost. We describe a simple and cost-effective protocol for the rapid analysis of chlorophylls, carotenoids and tocopherols using high-performance liquid chromatography (HPLC). Many existing methods are based on the expensive solvent acetonitrile, take a long time or do not include lutein epoxide and α-carotene. We aimed to develop an HPLC method which separates all major chlorophylls and carotenoids as well as lutein epoxide, α-carotene and α-tocopherol. Using a C30 -column and a mobile phase with a gradient of methanol, methyl-tert-butyl-ether (MTBE) and water, our method separates the above pigments and isoprenoids within 28 min. The broad applicability of our method is demonstrated using samples from various plant species and tissue types, e.g. leaves of Arabidopsis and avocado plants, several deciduous and conifer tree species, various crops, stems of parasitic dodder, fruit of tomato, roots of carrots and Chlorella algae. In comparison to previous methods, our method is very affordable, fast and versatile and can be used to analyze all major photosynthetic pigments that contribute to changes in leaf optical properties and which are of interest in most ecophysiological studies.

Correlation between different markers for the assessment of red chilli pepper powders stability during shelf-life.

Pungency and red colour of Capsicum powders deteriorate during processing and storage, resulting in a decrease in market value. Two varieties of pepper with different pungencies were monitored for capsaicinoids, colour and furosine. Aliquots were stored at room and at low temperature during one year. At low temperature all indicators were stable in both varieties, while at room temperature, redness and capsacinoids decreased significantly, while furosine increased. High correlation was found between those markers. The more pungent variety exhibited higher stability in terms of all parameters. Differences observed suggest a potential protective effect exerted by capsaicinoids on powder stability. The decrease in capsaicinoids and redness accompanied by furosine increase showed a linkage between those markers never reported before. Considering that capsaicinoids and furosine occurrence have strong impact on the nutritional profile, the findings of this work show relevant changes in the nutritional value of chilli pepper powder after storage.

Effects of pineapple byproduct and canola oil as fat replacers on physicochemical and sensory qualities of low-fat beef burger.

Pineapple byproduct and canola oil were evaluated as fat replacers on physicochemical and sensory characteristics of low-fat burgers. Five treatments were performed: conventional (CN, 20% fat) and four low-fat formulations (10% fat): control (CT), pineapple byproduct (PA), canola oil (CO), pineapple byproduct and canola oil (PC). Higher water and fat retention and lower cooking loss and diameter reduction were found in burgers with byproduct addition. In raw burgers, byproduct incorporation reduced L*, a*, and C* values, but these alterations were masked after cooking, leading to products similar to CN. Low-fat treatments were harder, chewier, and more cohesive than full-fat burgers. However, in Warner Bratzler shear measurements, PA and PC were as tender as CN. In QDA, no difference was found between CN and PC. Pineapple byproducts along with canola oil are promising fat replacers in beef burgers. In order to increase the feasibility of use of pineapple byproduct in the meat industry, alternative processes of byproduct preparation should be evaluated in future studies.

Impact of hedonic evaluation on consumers' preferences for beef attributes including its enrichment with n-3 and CLA fatty acids.

The impact of hedonic evaluation on consumers' preferences for beef attributes was evaluated (origin, animal diet, fat content, color, price) including its enrichment with omega-3 (n-3) and conjugated linoleic acid (CLA) fatty acids. One group of consumers (n=325) received information about n-3 and CLA, while the other group (n=322) received no information. Consumers conducted a Discrete Choice Experiment (DCE), using the recently developed Generalized Multinomial Logit model; followed by a blind hedonic evaluation of beef samples, which were identified after tasting, and finally repeated the DCE. Results showed that hedonic evaluation had a significant impact on consumers' preferences, which were similar after tasting for all consumers, with less emphasis on the fat content, color, and origin attributes and greater emphasis on animal diet. Preference for n-3 enriched beef increased, while preference for CLA enriched beef was still not significant after tasting. The information provided had a significant effect on consumers' beef preferences, but no significant impact on beef liking scores.

Short term supplementation rates to optimise vitamin E concentration for retail colour stability of Australian lamb meat.

The relationship between vitamin E supplementation rate and colour stability was investigated using 70 mixed sex 6-8 month old crossbred lambs. An initial group of 10 were slaughtered, while the remainder were fed a pellet ration containing either 30, 150, 275 or 400 IU vitamin E/kg ration or on green pasture for 56 days. After slaughter, carcases were halved; one side packed fresh (5 days) and the other in CO2 (21 days), both at 2°C. Five muscles were set for retail display for 96 h. The oxy/metmyoglobin ratio was measured every 12 h. Colour stability increased with increasing muscle vitamin E until an apparent maximum effect for vitamin E concentration (3.5-4.0mg α-tocopherol/kg tissue) was reached beyond which no further response was evident. This was reached within 3-4 weeks (275 IU treatment), and meat from these lambs should reach 60 h retail display with a satisfactory surface colour. This effect was most apparent in aerobic muscle types and meat aged post slaughter.

Effect of high pressure processing on dispersive and aggregative properties of almond milk.

BACKGROUND: A study was conducted to investigate the impact of high pressure (450 and 600 MPa at 30 °C) and thermal (72, 85 and 99 °C at 0.1 MPa) treatments on dispersive and aggregative characteristics of almond milk. Experiments were conducted using a kinetic pressure testing unit and water bath. Particle size distribution, microstructure, UV absorption spectra, pH and color changes of processed and unprocessed samples were analyzed. RESULTS: Raw almond milk represented the mono model particle size distribution with average particle diameters of 2 to 3 µm. Thermal or pressure treatment of almond milk shifted the particle size distribution towards right and increased particle size by five- to six-fold. Micrographs confirmed that both the treatments increased particle size due to aggregation of macromolecules. Pressure treatment produced relatively more and larger aggregates than those produced by heat treated samples. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k450MPa,30°C = 0.0058 s(-1) and k600MPa,30°C = 0.0095 s(-1) respectively. CONCLUSIONS: This study showed that dispersive and aggregative properties of high pressure and heat-treated almond milk were different due to differences in protein denaturation, particles coagulation and aggregates morphological characteristics. Knowledge gained from the study will help food processors to formulate novel plant-based beverages treated with high pressure. © 2015 Society of Chemical Industry.

Comparison of a multispectral vision system and a colorimeter for the assessment of meat color.

The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance properties, so several factors can influence the instrumental assessment of meat color. In order to assess whether two methods are equivalent, the variation due to these factors must be taken into account. A statistical analysis was conducted and showed that on a calibration sheet the two instruments are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments.

Effects of dry brining, liquid smoking and high-pressure treatment on the physical properties of aquacultured King salmon (Oncorhynchus tshawytscha) during refrigerated storage.

BACKGROUND: Aquacultured King salmon (Oncorhynchus tshawytscha) pieces were dry brined with a salt/brown sugar mix, dipped in liquid smoke for 3 min, vacuum packed, high hydrostatic pressure (HHP) treated at 600 or 200 MPa for 5 min and stored at 4 °C for up to 40 days. RESULTS: The surface redness (average a*) of the samples increased after dry brining, then decreased after liquid smoke treatment. HHP did not change the outside color of liquid-smoked samples. However, the inside color changed depending on pressure. HHP-treated control samples without dry brining and liquid smoking changed to a pale pink color. HHP at 600 MPa resulted in a significant increase in hardness. Compared with fresh samples, dry-brined samples had reduced water activity, while samples dipped in liquid smoke had lower pH values. CONCLUSION: Dry brining and liquid smoking protect the outside color of salmon against changes caused by HHP. The increase in hardness may counteract the softening of the smoked salmon tissue over time.

Variable effect of steam injection level on beef muscles: semitendinosus and biceps femoris cooked in convection-steam oven.

BACKGROUND: Combi ovens are used very often in restaurants to heat up food. According to the producers the equipment allows to cook meat portions which are more tender and flavoursome comparing to conventional cooking techniques. METHODS: Beef steaks from muscles semitendinosus and biceps femoris were cooked in convection-steam oven at three humidity levels: 10, 60 and 100%. Chemical composition, including total and insoluble collagen content and cook losses were analysed along with the texture and colour parameters. RESULTS: M. biceps femoris was the hardest and the most chewy at 100% steam saturation level and hardness measured for m. semitendinosus was the lowest at 10% of vapour injection. Changing the steam conditions in the oven chamber did not affect the detectable colour differences of m. biceps femoris, but it was significant for m. semitendinosus. Applying 100% steam saturation caused higher cook losses and the increase of insoluble collagen fractions in both analysed muscles. CONCLUSIONS: The results are beneficial for caterers using steam-convection ovens in terms of providing evidence that the heating conditions should be applied individually depending on the muscle used. The tenderness of m. semitendinosus muscle cooked at 10% steam saturation level was comparable to the tenderness obtained for the same muscle aged for 10 days and cooked with 100% steam saturation. Steaks from m. biceps femoris muscle should be cooked with maximum 60% saturation level to obtain higher tenderness.

Rapid detection of haloarchaeal carotenoids via liquid-liquid microextraction enabled direct TLC MALDI-MS.

For the first time, we demonstrate the use of TiO2 nanoparticles (NPs) for enhancing the carotenoid production by the extremophilic haloarchea, Haloferax mediterranei. TiO2 NPs at optimal concentration of 375 mg/L results in a 95% increase in the production of carotenoid pigment compared to the control (no TiO2 NPs). The carotenoid pigments extracted from TiO2 NPs treated H. mediterranei cells, were separated using thin layer chromatography (TLC). The separated carotenoid spots were subjected directly for MALDI MS detection. To limit the sample diffusion during matrix addition on TLC plates, a simple bordering mode was exercised. Using this method we were able to detect the pigments successfully using MALDI-MS, directly from TLC plates after separation. In addition, we also applied the Pt NPs capped with ODT via Liquid-liquid microextraction (LLME) for extracting the pigment molecules from the halobacteria in MALDI-MS. These novel NP approaches possess numerous advantages such as; rapidity, ease in synthesis, high sensitivity and low cost.

Quantitative Determination of Carthamin in Carthamus Red by 1H-NMR Spectroscopy.

Carthamus Red is a food colorant prepared from the petals of Carthamus tinctorius (Asteraceae) whose major pigment is carthamin. Since an authentic carthamin standard is difficult to obtain commercially for the preparation of calibration curves in HPLC assays, we applied (1)H-NMR spectroscopy to the quantitative determination of carthamin in commercial preparations of Carthamus Red. Carthamus Red was repeatedly extracted in methanol and the extract was dissolved in pyridine-d(5) containing hexamethyldisilane (HMD) prior to (1)H-NMR spectroscopic analysis. The carthamin contents were calculated from the ratios of singlet signal intensities at approximately σ: 9.3 derived from H-16 of carthamin to those of the HMD signal at σ: 0. The integral ratios exhibited good repeatability among NMR spectroscopic analyses. Both the intra-day and inter-day assay variations had coefficients of variation of <5%. Based on the coefficient of absorption, the carthamin contents of commercial preparations determined by (1)H-NMR spectroscopy correlated well with those determined by colorimetry, although the latter were always approximately 1.3-fold higher than the former, irrespective of the Carthamus Red preparations. In conclusion, the quantitative (1)H-NMR spectroscopy used in the present study is simple and rapid, requiring no carthamin standard for calibration. After HMD concentration has been corrected using certified reference materials, the carthamin contents determined by (1)H-NMR spectroscopy are System of Units (SI)-traceable.

Myoglobin chemistry and meat color.

Consumers rely heavily on fresh meat color as an indicator of wholesomeness at the point of sale, whereas cooked color is exploited as an indicator of doneness at the point of consumption. Deviations from the bright cherry-red color of fresh meat lead to product rejection and revenue loss. Myoglobin is the sarcoplasmic heme protein primarily responsible for the meat color, and the chemistry of myoglobin is species specific. The mechanistic interactions between myoglobin and multiple extrinsic and intrinsic factors govern the color of raw as well as cooked meats. The objective of this review is to provide an overview of the current research in meat color and how the findings are applied in the meat industry. Characterizing the fundamental basis of myoglobin's interactions with biomolecules in postmortem skeletal muscles is necessary to interpret the chemistry of meat color phenomena and to engineer innovative processing strategies to minimize meat discoloration-induced revenue loss to the agricultural economy.

Sweet potato-based complementary food for infants in low-income countries.

BACKGROUND: In low-income countries, most infants are given cereal-based complementary foods prepared at the household level. Such foods are high in phytate, which limits the bioavailability of nutrients, including iron, calcium, zinc, and in some cases proteins, which are crucial to the development of infants. OBJECTIVE: To compare the levels of macronutrients (protein, fat, and carbohydrate), gross energy, and fructose in sweet potato-based (denoted ComFa) formulations and enriched Weanimix (dehulled maize-dehulled soybean-groundnut blend with fish powder and sugar incorporated). The phytate level was also compared. METHODS: A composite flour of sweet potato and soybeans containing fish powder was processed by oven toasting as a home-based complementary food. Another blend containing skim milk powder was processed by extrusion cooking or roller drying as industrial-based prototypes. The macronutrient composition and the levels of fructose and phytate were determined in the ComFa formulations and enriched Weanimix. RESULTS: The ComFa formulations and the enriched Weanimix met the stipulated values in the Codex Alimentarius Commission standard for energy (400 kcal/100 g), protein (15 g/100 g), and fat (10 to 25 g/100 g) for complementary food, with the exception of the industrial-based ComFa formulations, which satisfied 83% of the protein requirement (15 g/100 g). The ComFa formulations had a quarter of the phytate level of enriched Weanimix. The fructose level in the sweet potato-based complementary foods was more than five times that in enriched Weanimix. CONCLUSIONS: The sweet potato-based formulations were superior to enriched Weanimix as complementary foods for infants in low-income countries, based on the fructose (which makes the porridge naturally sweet) and phytate levels.

Isolation, fractionation and characterization of melanin-like pigments from chestnut (Castanea mollissima) shells.

UNLABELLED: Melanins are known as versatile biopolymers, but the utilizations are restricted by their poor solubilities. Therefore, well soluble ones or their analogs are much desired. In this article, a new procedure was developed for fractionation of the pigments isolated from chestnut (Castanea mollissima) shells, and 3 fractions (Fr. 1, Fr. 2, and Fr. 3) were obtained. The solubilities of all the fractions in waters of different pH and in common organic solvents were studied. The physicochemical properties of the fractions were characterized for the first time on the basis of combined chemical analyses and spectroscopic methods including ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), electron spin resonance (ESR), and solid-state ¹³C nuclear magnetic resonance (¹³C-NMR). All the fractions could be bleached by NaOCl and H2O2 and give a positive reaction for polyphenols, which are usually used as typical tests for allomelanins. Their UV-Vis, FT-IR, and ESR spectra resembled those of synthetic and some natural melanins. Elemental data and quantitative analyses of ¹³C-NMR spectra revealed that pigment-bound proteins and polysaccharides were the most abundant in Fr. 1, while Fr. 2 was presented with the highest aromaticity. PRACTICAL APPLICATION: We provided a new, simple, and inexpensive method to fractionate the melanin-like pigments from chestnut shells. This technique can be used to produce natural melanin-like food colorants with different solubilities from chestnut shells.