Paul J. Sarnoski

Alterations in the sarcoplasmic protein fraction of beef muscle with postmortem aging and hydrodynamic pressure processing.

UNLABELLED Capillary electrophoresis (CE) and reversed-phase high performance liquid chromatography (RP-HPLC) analyses were utilized to detect differences in the sarcoplasmic protein fractions of beef strip loins subjected to aging and hydrodynamic pressure processing (HDP) treatments. At 48 h postmortem, strip loins (n = 12) were halved and subjected to control or HDP treatments. Following treatment, each half was divided into 3 portions which were aged for 0, 5, and 8 d. After each aging period, steaks were removed for Warner-Bratzler shear force (WBSF) analysis and for the extraction of sarcoplasmic proteins which were analyzed by CE and RP-HPLC. Aging by HDP interactions were not detected using either separation technique. With CE analysis, no HDP effects were observed; however, the relative peak area of 8 protein peaks ranging in size from 17 to >200 kDa were influenced by postmortem aging. Separation of proteins by RP-HPLC demonstrated that HDP influenced the relative size of 2 protein peaks while postmortem aging effects were observed in 6 peaks. Alterations in the sarcoplasmic protein fractions detected by both CE and RP-HPLC were correlated to WBSF measurements. Overall, data demonstrate that HDP has minimal effects on sarcoplasmic proteins and that aging related changes in the water soluble protein fractions of muscle may be useful as indirect indicators of beef tenderness. PRACTICAL APPLICATION Using 2 different postmortem tenderization techniques, aging and hydrodynamic pressure processing, this study demonstrates that postmortem changes in the soluble protein fraction of beef may be useful as potential indicators of meat tenderness.

Determination of Quality Attributes of Blue Crab (Callinectes sapidus) Meat by Electronic Nose and Draeger-Tube Analysis

ABSTRACT In this study, five groups of sequentially spoiled crabmeat were evaluated by a trained sensory panel, and these results were compared with the findings from a Cyranose 320 Electronic Nose and Draeger gas analyzer. Using the electronic nose with filtered compressed breathing air yielded the best results. Although this approach resulted in 100 % separation of the known groups, only 30% of the coded unknown samples were correctly identified. All 5 groups of samples analyzed using Draeger-Tubes were found to be significantly different at α = 0.05 using a Tukey-Kramer ANOVA statistical procedure. The coded unknown samples were correctly identified at a rate of 83%. The simplicity and precision of this latter procedure may present opportunities for use of Draeger-Tubes by crab processing industries and other food processing industries as an objective method for quality control.

Comparison of A-type Proanthocyanidins in Cranberry and Peanut Skin Extracts Using Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Cranberry products have long been used to treat urinary tract infections. It is believed that the A-type proanthocyanidins in cranberries contribute to this function. Peanut is one of the other, few food sources that primarily contain A-type proanthocyanidins. The skin on the outside of the peanut kernels (testa), which is treated as an agriculture waste product, contains high levels of A-type proanthocyanidins. In this study, an HPLC diol column separation method and MALDI-TOF MS were used to characterize and compare the proanthocyanidin compositions of peanut skins and cranberries. MALDI-TOF MS in linear mode was able to detect a group of proanthocyanidins with DP (degree of polymerization) 10 in peanut skin extract, but was only able to detect DP 8 in cranberry extract. The reflectron mode showed clusters of clear narrow peaks at DP 7 in peanut skin extract, while the highest DP resolved for cranberry extract was only 3 in reflectron mode. This might be due to the low response intensity of the cranberry samples with the current cleanup method and the matrix. Based on the resolved peaks in reflectron mode, pPeanut skins and cranberries have similar proanthocyanidins composition; they contain both A-type and B-type proanthocyanidins, with the A-type being predominant. This result may inspire future studies on the comparison of biological functions between peanut skins and cranberries and further comparison of their polymeric proanthocyanidin composition.

Polysaccharides as Alternative Moisture Retention Agents for Shrimp.

Phosphates are used as moisture retention agents (MRAs) by the shrimp industry. Although they are effective, phosphates are expensive, need to be listed on a food label, and overuse can often lead to a higher product cost for consumers. Polysaccharides were researched as alternative MRAs. Polysaccharides are usually inexpensive, are considered natural, and can have nutritional benefits. Research was conducted to determine whether polysaccharides yielded similar functional impacts as phosphates. Treatments included a 0.5% fibercolloid solution isolated from citrus peel, an 8% pectin solution, a 0.5% xanthan gum (XG) solution, a 1% carboxymethyl cellulose solution, and conventionally used 4% sodium tripolyphosphate (STP). Experimental treatments were compared to a distilled water control to gauge effectiveness. Freezing, boiling, and oven drying studies were performed to determine how moisture retention in shrimp differed using these different treatments. Water activity was measured to determine any potential differences in shelf life. Solution uptake was also determined to understand how well the treatments enhanced water binding. For moisture loss by freezing, 4% STP and the 0.5% fibercolloid solution functioned the best. The 4% STP treated shrimp lost the least amount of moisture during boiling. The 0.5% fibercolloid and 0.5% XG treatment outperformed phosphates in respect to moisture uptake ability. None of the treatments had a major effect on water activity. All treatments were rated similar in consumer sensory acceptability tests except for pectin, which was rated lower by the sensory panel. Overall, polysaccharides were found to be viable alternatives to phosphates.

Scavenging of Toxic Acrolein by Resveratrol and Hesperetin and Identification of Adducts.

The objective of this study was to investigate the ability of resveratrol and hesperetin to scavenge acrolein at pH 7.4 and 37 °C. About 6.4 or 5.2% of acrolein remained after reaction with resveratrol or hesperetin for 12 h at equimolar concentrations. An acrolein-resveratrol adduct and two acrolein-hesperetin adducts were isolated. Their structures were elucidated using mass and NMR spectroscopy. Acrolein reacted with resveratrol at the C-2 and C-3 positions through nucleophilic addition and formed an additional heterocyclic ring. Two similar monoacrolein-conjugated adducts were identified for hesperetin. Spectroscopic data suggested each acrolein-hesperetin adduct was a mixture of four stereoisomers due to the existence of two chiral carbon atoms. Yield of adducts was low at pH 5.4 but increased at pH 7.4 and 8.4. Higher pH also promoted the formation of diacrolein adducts. Results suggest that resveratrol and hesperetin exert health benefits in part through neutralizing toxic acrolein in vivo.

Colorimetric Evaluation of Mahi-Mahi and Tuna for Biogenic Amines

ABSTRACT The Food and Drug Administration and National Marine Fisheries Services grade tuna and mahi-mahi using trained sensory panels in order to determine the quality of these fish. A major concern with both species is the presence of histamine in the flesh, which can cause scombroid poisoning, a severe illness that can lead to death. Three different assays were examined in an attempt to correlate sample grade with biogenic amine content. The first method, acetic acid Dräger tubes, was only effective in identifying the highest grade (lowest quality) of mahi-mahi. The second method was a bromophenol blue (BPB) colorimetric strip that was sensitive to volatile biogenic amines. The third method was a histamine-specific enzyme-linked immunosorbant assay (ELISA) that detected analytes in the liquid phase. The results of the BPB and ELISA methods showed a correlation between sample grade and biogenic amine content for mahi-mahi. The same correlation was not observed with the tuna samples, likely due to physiological differences between the two species that affect the detection of the analytes.

THE MATRIX EFFECT OF TUNA AND MAHI-MAHI ON BIOGENIC AMINE DETECTION

Method of standard addition (MSA) is used to account for and quantify matrix effect. In this study, MSA was used to analyze the matrix effect of mahi-mahi and tuna in respect to biogenic amine detection. Two different detection methods were used in conjunction with the MSA procedure: a colorimetric strip that detects volatile biogenic amines and a histamine-specific ELISA (enzyme-linked immunosorbant assay), which detects histamine in the liquid phase. Trained sensory experts were utilized to grade mahi-mahi and tuna. The grading system acted as a measure of fish quality. A biogenic amine cocktail was created to act as the standard spike for the MSA procedure. It contained histamine and other biogenic amine compounds of varying volatility that are present in nature. The ELISA-MSA showed a clear correlation between increase in histamine and a lower quality sample (higher numerical grade). The colorimetric strips did not have a clear correlation between biogenic amine content and grade. Comparing the two methods demonstrates that the matrix effect of the tuna and mahi-mahi is likely more prominent with gas phase compounds than liquid phase compounds.

Postharvest Ripening of Noni Fruit (Morinda citrifolia) and the Microbial and Chemical Properties of Its Fermented Juice

The physiology of noni (Morinda citrifolia) fruit ripening, as well as the chemical and microbial properties of its fermented juice, were determined. The ripening fruit had a nonclimacteric respiratory pattern (34 mg CO2·kg−1h−1) and no detectable ethylene production. The fungus, Mucor circinelloides, was consistently isolated from fermented juice, with peak populations at 14 d coincident with an increase in headspace CO2 and a decline in pH and soluble solids. Bacterial populations were greatest at 42 d, with Erwinia pyrifoliae and Gluconobacter frateurii isolated from fermented juice. Sugar concentration (64.8 mg·mL−1) decreased by 37% after 7 d, while organic acids (26.6 mg·mL−1) were the highest at 28 d. Major non-volatile acids present in the fermented juice included acetic, ascorbic, dehydroascorbic, galacturonic, malonic, succinic, and tartaric acids.

Sensory and Flavor Characteristics of Tomato Juice from Garden Gem and Roma Tomatoes with Comparison to Commercial Tomato Juice

The objective of this study was to characterize the flavor of a premium Florida tomato variety that has significant potential for producing a high quality processed juice product. A high-quality Florida plum tomato variety (Garden Gem), and a typical grocery-store plum tomato variety (Roma) were thermally processed into tomato juices without any additives. The 2 pilot products and a popular commercially available tomato juice (low sodium with sugar and flavor added) were compared using sensory evaluation and instrumental analysis. Flavor compounds in these products were identified using dynamic headspace purge and trap-gas chromatography-mass spectrometry (PT-GC-MS) by MS library match and retention index and were semi-quantitated using internal standards. Color, uniformity, overall liking, tomato flavor, sweetness and texture were rated using a hedonic scale. Analysis of variance, correlation and principal component analysis were used to analyze both sensory and flavor data. Among the 3 products, Garden Gem juice was rated significantly (P < 0.05) higher for overall liking, tomato flavor, and sweetness by the 119 consumer panelists in both seasons. Garden Gem juice was found to contain higher levels of 3 sweet/fruity related aroma compounds: 6-methyl-5-hepten-2-one, linalool, and β-ionone. The commercial tomato juice contained a high level of the Maillard reaction-related notes furfural, dimethyl sulfide, and the least amount of green-related notes (hexanal, E-2-hexenal and Z-2-heptenal). The flavor profile of the Roma tomato juice was similar to Garden Gem juice except it contained substantially lower amounts of hexanal and 2-isobutylthiazole. The compound β-ionone (fruity note) was not detected in either the commercial or Roma juice. PRACTICAL APPLICATION This proof of concept study demonstrates that high flavor quality tomatoes can be used to create better tasting processed tomato products. The study also demonstrates how sensory preference can confer a potential market advantage over existing commercial products. The Garden Gem variety has potential to add desirable flavor attributes to processed tomato products. This research may also provide insights for product developers to which flavor volatiles best reflect sensory observations for different aspects of tomato flavor.

Sensory evaluation and flavour analysis of soymilk produced from lipoxygenase-free soya beans after modified processes and pulsed light treatment

Conventional static pulsed light (PL) treatment completely inactivated lipoxygenase (LOX) in whole soya beans to prevent off-flavours produced by LOX. However, the produced soymilk had inadequate values for total solid content. The fully soaked treatment (FST) and shaking treatment (SHT) were best in terms of increasing total solid content of soymilk from 3.7% for control soymilk to 4.6% and 4.3%, respectively; therefore, these treatments were chosen for soymilk sensory evaluation. No significant statistical differences in sensory evaluation scores existed between the control and soymilk produced from FST. The SHT for 130 s had higher overall liking (4.8) and flavour (4.6) scores compared with the control (4.1 and 3.9, respectively). Flavour analysis (purge and trap GC-MS) of the soymilk revealed that the ethanol peak area was the biggest difference between the treatments. This study demonstrated soya beans treated with PL have no negative sensory effect in general. Producing lipoxygenase-free soya bean is an important achievement to enhance soyfood products because lipoxygenase catalyses lipid oxidation, which takes place when lipoxygenase is released during soy milling.