Showing papers in "Journal of Food Science in 2012"

Food Protein‐Derived Bioactive Peptides: Production, Processing, and Potential Health Benefits

Abstract: Bioactive peptides (BAPs), derived through enzymatic hydrolysis of food proteins, have demonstrated potential for application as health-promoting agents against numerous human health and disease conditions, including cardiovascular disease, inflammation, and cancer. The feasibility of pharmacological application of these peptides depends on absorption and bioavailability in intact forms in target tissues, which in turn depends on structure of the peptides. Therefore, production and processing of peptides based on important structure-function parameters can lead to the production of potent peptides. This article reviews the literature on BAPs with emphasis on strategic production and processing methods as well as antihypertensive, anticancer, anticalmodulin, hypocholesterolemic, and multifunctional properties of the food protein-derived peptides. It is recommended that future research efforts on BAP should be directed toward elucidation of their in vivo molecular mechanisms of action, safety at various doses, and pharmacological activity in maintaining homeostasis during aberrant health conditions in human subjects.

Development and Application of a Database of Food Ingredient Fraud and Economically Motivated Adulteration from 1980 to 2010

Abstract: : Food ingredient fraud and economically motivated adulteration are emerging risks, but a comprehensive compilation of information about known problematic ingredients and detection methods does not currently exist. The objectives of this research were to collect such information from publicly available articles in scholarly journals and general media, organize into a database, and review and analyze the data to identify trends. The results summarized are a database that will be published in the US Pharmacopeial Convention's Food Chemicals Codex, 8th edition, and includes 1305 records, including 1000 records with analytical methods collected from 677 references. Olive oil, milk, honey, and saffron were the most common targets for adulteration reported in scholarly journals, and potentially harmful issues identified include spices diluted with lead chromate and lead tetraoxide, substitution of Chinese star anise with toxic Japanese star anise, and melamine adulteration of high protein content foods. High-performance liquid chromatography and infrared spectroscopy were the most common analytical detection procedures, and chemometrics data analysis was used in a large number of reports. Future expansion of this database will include additional publically available articles published before 1980 and in other languages, as well as data outside the public domain. The authors recommend in-depth analyses of individual incidents. Practical Application: This report describes the development and application of a database of food ingredient fraud issues from publicly available references. The database provides baseline information and data useful to governments, agencies, and individual companies assessing the risks of specific products produced in specific regions as well as products distributed and sold in other regions. In addition, the report describes current analytical technologies for detecting food fraud and identifies trends and developments.

Composition of Sugars, Organic Acids, and Total Phenolics in 25 Wild or Cultivated Berry Species

Abstract: Sugars, organic acids, and total phenolic content in fruit of 25 wild and cultivated berry species were identified and quantified with high-performance liquid chromatograph. The composition of sugars, organic acids, and total phenolic compounds in various species of Vaccinium, Rubus, Ribes, and Fragaria genus was evaluated. Additonally, total phenolics of less known berry species of the Morus, Amelanchier, Sorbus, Sambucus, Rosa, Lycium, Actinidia, and Aronia genus were determined in wild growing as well as in cultivated fruits. Significant differences in the concentration of sugars and organic acids were detected among the berry species. Glucose and fructose were the most abundant sugars in berry fruits and the major organic acids were malic and citric acid. However, in kiwi fruit, sucrose represented as much as 71.9% of total sugars. Sorbitol has been detected and quantified in chokeberry, rowanberry, and eastern shadbush fruit. The highest content of total analyzed sugars was determined in rowanberry fruit, followed by dog rose, eastern shadbush, hardy kiwifruit, American cranberry, chokeberry, and jostaberry fruit. Rowanberry stands out as the fruit with the highest content of total analyzed organic acids, followed by jostaberry, lingonberry, red gooseberry, hardy kiwifruit, and black currant. The berries of white gooseberry, black currant, red currant, and white currant had the lowest sugar/organic acid ratio and were thus perceptively the sourest species analyzed. On the other hand, the species with highest sugar/organic acid ratio were goji berry, eastern shadbush, black mulberry, and wild grown blackberry. The highest amounts of total phenols were quantified in chokeberry fruit. Wild strawberry, raspberry, and blackberry had 2- to 5-fold more total phenolics compared to cultivated plants. Practical Application: The fruit of analyzed berry species contained different levels of sugars, organic acids, and total phenolics. Moreover, it has been demonstrated that wild grown species generally contain more phenolics than cultivated ones. This information is interesting for nutritionists as well as berry growers and breeders who can promote the cultivation of species and new cultivars with higher phenolic content.

State of knowledge on amaranth grain: a comprehensive review.

Abstract: Amaranth grain is a highly nutritional pseudocereal with a superior amount of proteins when compared to true cereals. It is a reasonably well-balanced food with functional properties that have been shown to provide medicinal benefits. The health benefits attributed include decreasing plasma cholesterol levels, stimulating the immune system, exerting an antitumor activity, reducing blood glucose levels and improving conditions of hypertension and anemia. In addition, it has been reported to possess anti-allergic and antioxidant activities. The present article provides a comprehensive overview of amaranth grain that focuses on recent research reporting its use in the clinical practice and its possible benefits to human health.

Reutilization of Mango Byproducts: Study of the Effect of Extraction Solvent and Temperature on Their Antioxidant Properties

Abstract: Mango biowastes, obtained after processing, contain large amounts of compounds with antioxidant activity that can be reused to reduce their environmental impact. The present study evaluates the effect of solvent (methanol, ethanol, acetone, water, methanol:water (1:1), ethanol:water (1:1), and acetone:water (1:1)), and temperature (25, 50, and 75 ◦ C) on the efficiency of the extraction of antioxidants from mango peel and seed. Among the factors optimized, extraction solvent was the most important. The solvents that best obtained extracts with high antioxidant capacity were methanol, methanol:water, ethanol:water, and acetone:water (β-carotene test, antioxidant activity coefficient 173 to 926; thiobarbituric acid reactive substances test, inhibition ratio 15% to 89%; 2,2 � -azino-bis-(3-ethylbenzothiazoline)-6- sulfonic acid ABTS + ; and 2,2-diphenyl-1-picrylhydrazyl DPPH scavenging, 7 to 22 and 8 to 28 g trolox equivalent antioxidant capacity (TE) per 100 g mango biowaste on a dry matter basis (DW)). Similarly, the flavonoid (0.21 to 1.4 g (+)-catechin equivalents per 100 g DW), tannin (3.8 to 14 g tannic acid equivalents per 100 g DW), and proanthocyanidin (0.23 to 7.8 g leucoanthocyanidin equivalents per 100 g DW) content was highest in the peel extracts obtainedwithmethanol,ethanol:water,oracetone:waterandintheseedextractsobtainedwithmethanoloracetone:water. From the perspective of food security, it is advisable to choose ethanol (which also has a notable antioxidant content), ethanol:water, or acetone:water, as they are all solvents that can be used in compliance with good manufacturing practice. In general, increasing temperature improves the capacity of the extracts obtained from mango peel and seed to inhibit lipid peroxidation; however, its effect on the extraction of phytochemical compounds or on the capacity of the extracts to scavenge free radicals was negligible in comparison to that of the solvent.

Cold plasma reduction of Salmonella and Escherichia coli O157:H7 on almonds using ambient pressure gases.

Abstract: Contamination of raw nuts, including almonds, is a food safety concern. Cold plasma is a novel antimicrobial intervention that can eliminate foodborne pathogens. The objective of this work was to evaluate the efficacy of rapid cold plasma treatments in eliminating Salmonella and Escherichia coli O157:H7 from dry almonds. Three isolates of Salmonella (S. Anatum F4317, S. Stanley H0558, and S. Enteritidis PT30) and 3 isolates of E. coli O157:H7 (C9490, ATCC 35150, and ATCC 43894) were separately grown and spot-inoculated (10 μL) onto whole almonds and allowed to dry for 10 min. Inoculated almonds were treated with a cold plasma jet, with treatment variables evaluated in a factorial design for each isolate: time, distance, and feed gas. Treatment time was 0 s (control), 10 s, or 20 s. Distance from the emitter was 2, 4, or 6 cm. Feed gas was dry air or nitrogen. After treatment, the almonds were sampled using swabs. Survivors were enumerated on tryptic soy agar (TSA) plates. Cold plasma significantly reduced both pathogens on almonds. The greatest reduction observed was 1.34 log cfu/mL reduction of E. coli O157:H7 C9490 after 20 s treatment at 6 cm spacing. The interaction of treatment time with distance from plasma emitter head was complex, and isolate-dependent. Longer duration of treatment did not always result in enhanced reductions. In general, nitrogen as a feed gas resulted in a reduced antimicrobial efficacy compared to dry air. These results indicate that short pulses of atmospheric pressure cold plasma can significantly reduce Salmonella and E. coli O157:H7 on almonds.

Physical-mechanical properties of agar/κ-carrageenan blend film and derived clay nanocomposite film.

Abstract: Binary blend films with different mixing ratio of agar and κ-carrageenan were prepared using a solution casting method with and without nanoclay and the effect of their composition on the mechanical, water vapor barrier, and water resistance properties was tested. The tensile strength (TS) of the κ-carrageenan film was greater than that of agar film. The water vapor permeability (WVP) of the agar film was lower than that of κ-carrageenan film, the swelling ratio (SR) and water solubility (WS) of κ-carrageenan film were higher than those of agar film. Each property of the binary blend films varied proportionately depending on the mixing ratio of each component. The XRD result indicated that the nanocomposite with agar/κ-carrageenan/clay (Cloisite(®) Na(+)) was intercalated. Consequently, the mechanical strength, water vapor barrier properties, and water contact angle (CA) were significantly (P < 0.05) improved through nanocomposite formation.

Textural Characteristic, Antioxidant Activity, Sugar, Organic Acid, and Phenolic Profiles of 10 Promising Jujube (Ziziphus jujuba Mill.) Selections

Abstract: Ten promising jujubes were analyzed for textural characteristic (hardness), antioxidant activity, sugar, organic acid, and phenolic profiles. Total phenolic content (TP) measured by Folin–Ciocalteu method ranged from 275.6 to 541.8 mg of gallic acid equivalents per 100 g fresh weight (mg GAE/100 g FW). Four sugars (rhamnose, fructose, sucrose, and glucose), 3 organic acids (malic, citric, and succinic acids), and 11 phenolic compounds (gallic acid, protocatechuic acid, cinnamic acid, chlorogenic acid, caffeic acid, ferulic acid, ellagic acid, catechin, epicatechin, rutin, and quercetin) were identified and quantified by high-performance liquid chromatography in jujube fruits. The results showed that ascorbic acid and proanthocyanidins contents were positively correlated with hardness, and antioxidant activity was well correlated with TP content. Among 10 jujube cultivars, Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption containing high levels of total soluble solids, total sugars, fructose, and glucose, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants. Practical Application: Genotype is the main factor influencing the composition of bioactive compounds in jujubes. Zizyphus jujuba cv. Qingjianmuzao is good for direct consumption, while Zizyphus jujuba cv. Jiaxianmuzao could be an important dietary source of natural antioxidants for prevention of diseases caused by oxidative stress.

Isolation and biological activities of decanal, linalool, valencene, and octanal from sweet orange oil.

Abstract: Product 1 (82.25% valencene), product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) were isolated from sweet orange oil by combined usage of molecular distillation and column chromatography. The antioxidant activity of sweet orange oil and these products was investigated using 2,2-diphenyl-1-picrylhydrazyl and reducing power assays. In this test, product 1 (82.25% valencene), product 2 (73.36% decanal), and product 4 (90.61% linalool) had antioxidant activity, but lower than sweet orange oil. The antimicrobial activity was investigated in order to evaluate their efficacy against 5 microorganisms. The results showed that sweet orange oil, product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) had inhibitory and bactericidal effect on the test microorganisms (except Penicillium citrinum). Valencene did not show any inhibitory effect. Saccharomyces cerivisiae was more susceptible, especially to the crude sweet orange oil (minimal inhibitory concentration 6.25 μL/mL). The cytotoxicity was evaluated on Hela cells using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. All test samples showed significant cytotoxicity on the cell lines with IC(50) values much less than 20 μg/mL.

Production Technologies for Reduced Alcoholic Wines

Abstract: The production and sale of alcohol-reduced wines, and the lowering of ethanol concentration in wines with alcohol levels greater than acceptable for a specific wine style, poses a number of technical and marketing challenges. Several engineering solutions and wine production strategies that focus upon pre- or postfermentation technologies have been described and patented for production of wines with lower ethanol concentrations than would naturally arise through normal fermentation and wine production techniques. However, consumer perception and acceptance of the sensory quality of wines manufactured by techniques that utilize thermal distillation for alcohol removal is generally unfavorable. This negative perception from consumers has focused attention on nonthermal production processes and the development or selection of specific yeast strains with downregulated or modified gene expression for alcohol production. The information presented in this review will allow winemakers to assess the relative technical merits of each of the technologies described and make decisions regarding implementation of novel winemaking techniques for reducing ethanol concentration in wine.

Antioxidant Activities and Phenolic Compounds of Pigmented Rice Bran Extracts

Abstract: This study was carried out to investigate the antioxidant activities and phenolic compounds of pigmented rice (black, red, and green rice) and brown rice brans. Antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, 2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulfonic acid) (ABTS) radical cation assay, reducing power, and chelating ability. Phenolic compounds were measured by using HPLC. Pigmented rice brans were extracted by using aqueous mixtures of acetone, ethanol, and methanol to determine the most effective extraction solvent. Of all solvents examined, extract from 40:60 acetone–water mixtures (v/v) provided the highest DPPH radical assay as well as the highest total phenolic and flavonoid content. We finally selected 40% acetone as an extraction solvent for antioxidant study of pigmented rice bran. Antioxidant activities of 40% acetone extracts of pigmented rice bran, measured in the range of 0 to 1500 μg/mL. At 500 μg/mL concentration, red rice bran, which had the highest total phenolic (259.5 μg/mg) and total flavonoid (187.4 μg/mg) contents, showed the highest antioxidant activity: 83.6%, 71.5%, 1.2%, and 16.4% for DPPH radical assay, ABTS radical cation assay, reducing power, and chelating ability, respectively. Red rice bran showed a lower EC50 value (112.6 μg/mL) than that of butylated hydroxytoluene (144.5 μg/mL) from the DPPH radical assay. The major phenolic acids of red rice bran were ferulic, vanillic and p-coumaric acids. The results indicated pigmented rice bran might be used as a natural antioxidant. Practical Application: The present study revealed black and red rice bran shows high antioxidant activities and they contain high amount of phenolic compounds. Indeed, black and red rice bran could be better raw materials for manufacturing the food with high antioxidant activity.

Fungal decay and shelf life of oranges coated with chitosan and bergamot, thyme, and tea tree essential oils.

Abstract: UNLABELLED Chitosan coatings, containing or not essential oils (bergamot, thyme and tea tree oil), were applied to oranges (cv. Navel Powell). Antifungal effect was evaluated by applying coatings before and after inoculating the fruit with Penicillium italicum CECT 2294 (10(5) spores/mL), preventive and curative treatments, respectively. The effect of coatings on the quality parameters (acidity, pH, soluble solids, juice percentage, weight loss, firmness, color parameters, and respiration rate) was controlled for the different oranges samples throughout the cold storage time. Preventive antimicrobial treatments with coatings containing tea tree oil were the most effective with a reduction of the microbial growth (expressed as the percentage of infected samples) of 50%, as compared to the uncoated samples. The coatings did not lead to any relevant changes in the development of the sample quality parameters throughout the cold storage, except for a slightly reduced loss of both weight and firmness when the coatings contained bergamot oil. PRACTICAL APPLICATIONS Results of this study are a useful tool for the development of new environmental friendly and healthier commercial applications in the control of the main postharvest fungal decay of citrus fruits.

Characterization of Edible Coatings Consisting of Pea Starch, Whey Protein Isolate, and Carnauba Wax and their Effects on Oil Rancidity and Sensory Properties of Walnuts and Pine Nuts

Abstract: Edible coatings made of whey protein isolate (WPI), pea starch (PS), and their combinations with carnauba wax (CW) were prepared and characterized. WPI combined with CW formed stable emulsion while PS with CW formed unstable emulsion and both formulations produced non-homogeneous films. Addition of PS to WPI: CW combination at the ratio of 1: 1: 1, respectively, resulted in stable emulsion and homogenous films. The emulsion PS: WPI: CW (1: 1: 2) was stable and formed a continuous film but had less homogenous droplets size distribution when compared to 1: 1: 1 film. Combined films had a reduced tensile strength and elongation compared to single component films. WPI : CW (1: 1) films had higher elastic modulus than the WPI films, but the modulus reduced by the addition of PS. All the coating formulations were effective in preventing oxidative and hydrolytic rancidity of walnuts and pine nuts stored at 25 °C throughout the storage (12 d) but were less effective at 50 °C. Increasing the concentration of CW from 1: 1: 1 to 1: 1: 2 in PS: WPI: CW formulation did not contribute in further prevention of oil rancidity at 25 °C. Using of PS: WPI: CW (1: 1: 1) coating on both nuts significantly (P < 0.05) improved their smoothness and taste but the PS: WPI: CW (1: 1: 2) coatings imparted unacceptable yellowish color on walnuts. Practical Application: Edible coating of walnuts and pine nuts by whey protein isolate, pea starch, and carnauba wax reduced the oxidative and hydrolytic rancidity of the nuts and improved sensory characteristics.

Effect of different drying methods and storage time on the retention of bioactive compounds and antibacterial activity of wine grape pomace (Pinot Noir and Merlot).

Abstract: The effects of different drying methods (40 °C conventional and vacuum oven, 25 °C ambient air and freeze dry) on the stability of two red wine grape (Pinot Noir, PN and Merlot, M) byproducts, pomace containing skins and seeds (P) and pomace containing skins only (S) were investigated. Freeze dried samples retained the highest bioactive compounds with total phenolic content (TPC) of 21.19–67.74 mg GAE/g d.m., anthocyanin content (ACY) of 0.35–0.76 mg Mal-3-glu/g d.m., DPPH antiradical scavenge activity (ARS) of 22.01–37.46 mg AAE/g d.m., and total flavanol content (TFC) of 30.16–106.61 mg CE/g d.m., followed with ambient air dried samples. All samples lost significant amount of bioactive compounds during 16 wk of storage at 15 ± 2 °C, in which ambient air and freeze dried samples had TPC reduction of 32–56% and 35–58%, respectively, but ARS in PN-P and M-P still remained more than 50 mg TE/g d.m. Overall, TPC, ARS, and TFC were higher in PN than in M, and higher in pomace than in skins, while reverse results were observed in ACY. Pomace extracts showed higher antibacterial efficiency against Listeria innocua ATCC 51142 than Escherichia coli ATCC 25922 with minimal inhibition concentration (MIC) of 3%, 6%, 4%, and 9% against E. coli, and 2%, 7%, 3%, and 8% against L. innocua for PN-P, PN-S, M-P, and M-S samples, respectively. Dietary fiber content of samples was 57–63% of total dry matter. This study demonstrated that Pinot Noir and Merlot pomace are good sources of antioxidant dietary fibers and may be incorporated into various food products as a functional ingredient. Practical Application: Wine grape pomace (WGP), the byproduct of wine making, is a good source of polyphenols and dietary fibers and may be incorporated into various food products as a functional ingredient. This study reported the effect of four drying methods and storage at 15 ± 2 °C up to 4 months on the retention of polyphenols and antioxidant activity in two types of red WGP (with and without seeds). Antibacterial activity, dietary fiber content and the basic physicochemical properties of dried pomace powder were also reported. The information is essential for developing specific applications of the pomace.

Optimization of a Sponge Cake Formulation with Inulin as Fat Replacer: Structure, Physicochemical, and Sensory Properties

Abstract: The effects of several fat replacement levels (0%, 35%, 50%, 70%, and 100%) by inulin in sponge cake microstructure and physicochemical properties were studied. Oil substitution for inulin decreased significantly (P < 0.05) batter viscosity, giving heterogeneous bubbles size distributions as it was observed by light microscopy. Using confocal laser scanning microscopy the fat was observed to be located at the bubbles’ interface, enabling an optimum crumb cake structure development during baking. Cryo-SEM micrographs of cake crumbs showed a continuous matrix with embedded starch granules and coated with oil; when fat replacement levels increased, starch granules appeared as detached structures. Cakes with fat replacement up to 70% had a high crumb air cell values; they were softer and rated as acceptable by an untrained sensory panel (n = 51). So, the reformulation of a standard sponge cake recipe to obtain a new product with additional health benefits and accepted by consumers is achieved.

High Performance Liquid Chromatography Analysis of Anthocyanins in Bilberries (Vaccinium myrtillus L.), Blueberries (Vaccinium corymbosum L.), and Corresponding Juices

Abstract: In the present study the anthocyanin content of commercially available bilberry juices and fresh fruits were quantified by using 15 authentic anthocyanin standards via high performance liquid chromatography with an ultra-violet detector (HPLC-UV/VIS). Delphinidin-3-O-glucopyranoside, delphinidin-3-O-galactopyranoside, and cyanidin-3-O-arabinopyranoside were the major anthocyanins found in juices, nectar, and fresh bilberries. In contrast, fresh blueberries had higher concentrations of malvidin-3-O-arabinopyranoside and petunidin-3-O-galactopyranoside. Up to 438 mg anthocyanins per 100 g fresh weight (2762 mg/100 g dry weight (DW)) were detected in blueberries from various sources, whereas bilberries contained a maximum of 1017 mg anthocyanins per 100 g fresh weight (7465 mg/100 g DW). Commercially available bilberry and blueberry juices (n= 9) as well as nectars (n= 4) were also analyzed. Anthocyanin concentrations of juices (1610 mg/L to 5963 mg/L) and nectar from bilberries (656 mg/L to 1529 mg/L) were higher than those of blueberry juices (417 mg/L) and nectar (258 mg/L to 386 mg/L). We conclude that using several authentic anthocyanin references to quantify anthocyanin contents indicated them to be up to 53% and 64% higher in fresh bilberries and blueberries, respectively, than previously reported using cyanidin-3-O-glucoside. This study has also demonstrated that commercially available juices produced from bilberries contain much higher anthocyanin concentrations than those from blueberries. Practical Application: We have investigated the contents of a special class of antioxidants, namely anthocyanins in blueberry and billberry fruits and juices commercially available in Germany. To achieve reliable data we have used authentic standards for the first time. We think that our results are important in the field of nutritional intake of this important class of polyphenols and fruit juice companies get a closer insight in the occurrence of these antioxidants in market samples to be used in food composition databases and for nutritional survey.

Chitosan-based Edible Coatings for Quality Preservation of Postharvest Whiteleg Shrimp (Litopenaeus vannamei)

Abstract: Postharvest shrimp is highly susceptible to both microbiological spoilage and endogenous enzymatic browning, so it should be preserved properly using effective and appropriate methods. The effects of 1.0% and 1.5% O-carboxymethyl chitosan (CMC) and 1.0% and 1.5% chitosan (CH) coatings on the quality changes of whiteleg shrimp (Litopenaeus vannamei) during refrigerated storage (0 ± 1 °C) of 10 d were investigated. The pretreatment with CMC and CH solution (1.0% or 1.5%) retarded growth of psychrophilic bacteria throughout storage in comparison with the control (P < 0.05). The lower increases in pH and total volatile base (TVB) content were obtained in the shrimp treated with CMC and CH solution at both levels, compared with the control samples (P < 0.05). Loss in freshness and melanosis decreased after the shrimp was treated with CMC and CH. In addition, CMC and CH (1.0% or 1.5%) showed inhibitory activity toward total viable bacteria counts of white shrimp in a dose-dependent manner. Therefore, chitosan and O-carboxymethyl chitosan can be used as promising melanosis inhibitors as well as antimicrobial agents during refrigerated storage. Practical Application: The main practical application behind the development of chitosan (CH) and O-carboxymethyl chitosan (CMC) used to preserve postharvest whiteleg shrimp lies with the fact that these polysaccharides represent a renewable source of natural biodegradable polymers and meet with the emergence of more and more food safety problems. Both CMC and CH can be used as food preservatives to extend shrimp shelf life. However, CMC is more convenient due to its solubility. In the future, CMC will be used in the food processing industry because of its soluble, compatible, antimicrobial, and antioxidative characteristics.

Inactivation of Listeria monocytogenes on ham and bologna using pectin-based apple, carrot, and hibiscus edible films containing carvacrol and cinnamaldehyde.

Abstract: Edible films can be used as wrapping material on food products to reduce surface contamination. The incorporation of antimicrobials into edible films could serve as an additional barrier against pathogenic and spoilage microorganisms that contaminate food surfaces. The objective of this study was to investigate the antimicrobial effects of carvacrol and cinnamaldehyde, incorporated into apple, carrot, and hibiscus-based edible films against Listeria monocytogenes on contaminated ham and bologna. Ham or bologna samples were inoculated with L. monocytogenes and dried for 30 min, then surface wrapped with edible films containing the antimicrobials at various concentrations. The inoculated, film-wrapped samples were stored at 4 °C. Samples were taken at day 0, 3, and 7 for enumeration of surviving L. monocytogenes by plating on appropriate media. Carvacrol films showed better antimicrobial activity than cinnamaldehyde films. Compared to control films without antimicrobials, films with 3% carvacrol induced 1 to 3, 2 to 3, and 2 to 3 log CFU/g reductions on ham and bologna at day 0, 3, and 7, respectively. Corresponding reductions with 1.5% carvacrol were 0.5 to 1, 1 to 1.5, and 1 to 2 logs, respectively. At day 7, films with 3% cinnamaldehyde reduced L. monocytogenes population by 0.5 to 1.5 and 0.5 to 1.0 logs on ham and bologna, respectively. Inactivation by apple films was greater than that by carrot or hibiscus films. Apple films containing 3% carvacrol reduced L. monocytogenes population on ham by 3 logs CFU/g on day 0 which was 1 to 2 logs greater than that by carrot and hibiscus films. Films were more effective on ham than on bologna. The food industry and consumers could use these films to control surface contamination by pathogenic microorganisms. Practical Application: Antimicrobial edible, food-compatible film wraps prepared from apples, carrots, and hibiscus calyces can be used by the food industry to inactivate Listeria monocytogenes on widely consumed ready to eat meat products such as bologna and ham. This study provides a scientific basis for large-scale application of edible fruit- and vegetable-based antimicrobial films on foods to improve microbial food safety.

Inhibition of Ostwald ripening in model beverage emulsions by addition of poorly water soluble triglyceride oils.

Abstract: Beverage emulsions containing flavor oils that have a relatively high water-solubility are unstable to droplet growth due to Ostwald ripening. The aim of this study was to improve the stability of model beverage emulsions to this kind of droplet growth by incorporating poorly water-soluble triglyceride oils. High pressure homogenization was used to prepare a series of 5 wt% oil-in-water emulsions stabilized by modified starch that had different lipid phase compositions (orange oil : corn oil). Emulsions prepared using only orange oil as the lipid phase were highly unstable to droplet growth during storage, which was attributed to Ostwald ripening resulting from the relatively high water-solubility of orange oil. Droplet growth could be effectively inhibited by incorporating ≥ 10% corn oil into the lipid phase prior to homogenization. In addition, creaming was also retarded because the lipid phase density was closer to that of the aqueous phase density. These results illustrate a simple method of improving the physical stability of orange oil emulsions for utilization in the food, beverage, and fragrance industries.

Increasing the applications of Crocus sativus flowers as natural antioxidants.

Abstract: UNLABELLED Large amounts of floral bio-residues (92.6 g per 100 g of flowers) are generated and wasted in the production of saffron (Crocus sativus) spice. Progress in mechanization of saffron crop offer the opportunity to expand the uses of C. sativus flowers, beyond the spice (dried stigmas). The antioxidant potential of flowers of saffron, their separate parts (tepals, stamens, styles, and stigmas) and floral bio-residues were evaluated by 4 in vitro assays: lipid peroxidation, deoxyribose assay, Rancimat test, and Trolox equivalent antioxidant capacity. Phenolic content and crocetin ester composition were also determined. All the samples studied showed to be potential antioxidants. The highest phenolic, flavonoid, and anthocyanin contents were observed in tepals. Stamens showed lower phenolic, flavonoid, and anthocyanin contents than those of whole flowers, tepals, and floral bio-residues. Crocetin esters were not found in tepals or stamens. Stamens exhibited the most potent LOO(•) and OH(•) radicals scavenging activity, being higher than those of food antioxidant propyl gallate. Flowers of saffron, tepals, stamens, styles, and floral bio-residues showed LOO(•), OH(•), and ABTS(•-) radicals scavenging activity, while stigmas showed LOO(•) and ABTS(•-) radicals scavenging activity. All samples studied improved the oxidative stability of sunflower oil in Rancimat test. These antioxidant properties could suggest the application of this floral material as functional ingredients with the subsequent added value. PRACTICAL APPLICATION Saffron spice, the most valuable spice worldwide, is the dried stigma that only represents 7.4% of Crocus sativus flowers. Other parts of the flowers different to stigmas are discarded. Flower harvest and all the postharvest steps to produce saffron spice are performed manually. Mechanization of flower collection, stigma separation, and dehydration process is a revolution in saffron spice production, which increases the productive capacity making it possible to extend the uses of C. sativus flowers, beyond the production of saffron spice. Flowers possessed high-phenolic content and excellent antioxidant properties that could contribute to their application as functional ingredients.

Chemical Composition, Antioxidant, and Antimicrobial Activities of Essential Oil from Pine Needle (Cedrus deodara)

Abstract: The chemical composition of essential oil from pine needles (Cedrus deodara) was determined, and its antioxidant and antimicrobial activities were evaluated. Twenty-three components, representing 95.79% of the oil, were identified by gas chromatography mass spectrometry. The main components include α-terpineol (30.2%), linalool (24.47%), limonene (17.01%), anethole (14.57%), caryophyllene (3.14%), and eugenol (2.14%). Pine needle essential oil showed remarkable antioxidant activity in scavenging free radicals, in lipid peroxidation, and in reducing power assays. Moreover, the essential oil revealed strong antimicrobial activity against typical food-borne microorganisms, with minimum inhibitory concentration and minimum bactericidal concentration values of 0.2 to 1.56 and 0.39 to 6.25 μg/mL, respectively. Transmission electron microscope observation ascertained that the bactericidal mechanism of pine needle essential oil may be the induction of cytoplasmic outflow and plasmolysis. These results suggest that the essential oil from pine needles has potential to be used as a natural antioxidant and antimicrobial agent in food processing. Practical Application: The present study provides a theoretical basis for the potential application of essential oil from pine needles (C. deodara) to be used as a natural resource of antioxidant and antimicrobial agents in food industry.

Comparative Study on the Antioxidant Capacity and Cholinesterase Inhibitory Activity of Citrus aurantifolia Swingle, C. aurantium L., and C. bergamia Risso and Poit. Peel Essential Oils

Abstract: The interest in medicinal plant research and in the aroma-therapeutic effects of essential oils in humans has increased in recent years, especially for the treatment of pathologies of relevant social impact such as Alzheimer's disease. The present study was taken up to evaluate the antioxidant capacity and the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the peel essential oils from three Citrus species, C. aurantifolia Swingle, C. aurantium L., and C. bergamia Risso & Poit. Essential oils were analyzed by GC and GC-MS and they contain mainly limonene, α-pinene, β-pinene, γ-terpinene, and linalyl acetate. C. aurantifolia oil showed the highest radical scavenging activity on ABTS assay (IC50 value of 19.6 μg/mL), while C. bergamia exhibited a good antioxidant activity evaluated by the β-carotene bleaching test (IC50= 42.6 μg/mL after 60 min of incubation). C. aurantifolia inhibited more selectively AChE. Obtained data suggest a potential use of Citrus oils as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly. Practical Application: The demonstrated antioxidant activity and procholinesterase properties of Citrus essential oils suggested their use as a new potential source of natural antioxidant to added as extra-nutrient for using in food industries as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly.

Isolation and identification of an exopolysaccharide-producing lactic acid bacterium strain from Chinese Paocai and biosorption of Pb(II) by its exopolysaccharide.

Abstract: Lactic acid bacteria isolated from various traditional Chinese fermented foods were screened for the production of exopolysaccharides (EPS). The strain 70810 from Chinese Paocai, which was identified as Lactobacillus plantarum (HQ259238) by morphological, physiological, biochemical, and 16S rDNA tests, was selected due to its highest EPS production capability (0.859 g/L) for further study. Biosorption of Pb(II) from aqueous solutions by 70810 EPS was studied with parameters of initial pH, contact time, initial Pb(II) concentration, adsorbent dosage, and temperature, respectively. Maximum adsorption of Pb(II) was observed at pH 5, 30 °C, and 6 h, respectively. The adsorption capacity was also found to be dependent upon initial Pb(II) concentration and adsorbent dosage. Surface adsorption of the metal at surface of 70810 EPS was confirmed through scanning electron microscopy. Fourier transform infrared spectroscopy spectra analysis indicated that some functional groups (for example, –OH, COO–, C=O, and –NH) of 70810 EPS were involved in Pb(II) biosorption process. Practical Application: Lactobacillus plantarum 70810 can be used as a starter culture for the production of some fermented foods (for example, yoghurt or fermented soybean milk) and the production of EPS that can meet consumer′s demand for products with low levels of additives. The EPS may be used as a potential biosorbent for the removal of heavy metal from environment and these fermented foods maybe have the potential effect to excrete lead from human body.

Stability of Anthocyanin‐Rich W/O/W‐Emulsions Designed for Intestinal Release in Gastrointestinal Environment

Abstract: Anthocyanins belong to the most important hydrophilic plant pigments. Outside their natural environment, these molecules are extremely unstable. Encapsulating them in submicron-sized containers is one possibility to stabilize them for the use in bioactivity studies or functional foods. The containers have to be designed for a target release in the human gastrointestinal system. In this contribution, an anthocyanin-rich bilberry extract was encapsulated in the inner aqueous phase of water-in-oil-in-water-double emulsions. The physical stability as well as the release of free fatty acids and encapsulated, bioactive substances from the emulsions during an in vitro gastrointestinal passage were investigated. The focus was on the influence of emulsion microstructural parameters (for example, inner and outer droplet size, disperse phase content) and required additives (emulsifier systems), respectively. It could be shown that it is possible to stabilize anthocyanins in the inner phase of double emulsions. The release rate of free fatty acids during incubation was independent of the emulsifier used. However, the exterior (O/W)-emulsifier has an impact on the stability of multiple emulsions in gastrointestinal environment and, thus, the location of release. Long-chained emulsifiers like whey proteins are most suitable to transport a maximum amount of bioactive substances to the effective location, being the small intestine for anthocyanins. In addition, it was shown that the dominating release mechanism for entrapped matter was coalescence of the interior W(1) -droplets with the surrounding W(2) -phase.

Sensory characteristics and relative sweetness of tagatose and other sweeteners.

Abstract: The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener with various functional properties, compared to other sweeteners (sucrose, sucralose, erythritol, rebaudioside A), over a wide range of sweetness commonly found in foods and beverages (3% to 20% sucrose [w/v]). A total of 34 subjects evaluated aqueous solutions of the 5 sweeteners for the perceived intensities of sweetness, bitterness, astringency, chemical-like sensations, and sweet aftertaste, using the general version of the Labeled Magnitude Scale. The relationship between the physical concentrations of the sweeteners and their perceived sweetness (that is, psychophysical functions) was derived to quantify the relative sweetness and potency of the sweeteners. The results suggest that tagatose elicits a sweet taste without undesirable qualities (bitterness, astringency, chemical-like sensations). Out of the 5 sweeteners tested, rebaudioside A was the only sweetener with notable bitterness and chemical-like sensations, which became progressively intense with increasing concentration (P 1), whereas the high-potency sweeteners (sucralose, rebaudioside A) yielded much flatter sweetness functions (slopes < 1). Because the sweetness of tagatose and sucrose grew at near-identical rates (slope = 1.41 and 1.40, respectively), tagatose produced about the same relative sweetness to sucrose across the concentrations tested. However, the relative sweetness of other sweeteners to sucrose was highly concentration dependent. Consequently, sweetness potencies of other sweeteners varied across the concentrations tested, ranging from 0.50 to 0.78 for erythritol, 220 to 1900 for sucralose, and 300 to 440 for rebaudioside A, while tagatose was estimated to be approximately 0.90 times as potent as sucrose irrespective of concentration. Practical Application: The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener, compared to other sweeteners. Study results suggest that tagatose elicits a sweet taste without undesirable qualities over a wide range of concentrations. Tagatose produced about the same relative sweetness to sucrose across the concentrations tested, while the relative sweetness of other sweeteners was highly concentration dependent. The present data provide a general guideline when considering the use of tagatose and other sweeteners in foods and beverages.

Cassava starch-based films plasticized with sucrose and inverted sugar and reinforced with cellulose nanocrystals.

Abstract: Bionanocomposites films of cassava starch plasticized with sucrose and inverted sugar and reinforced by cellulose nanocrystals (CNCs) were prepared by solution casting method incorporating 0.1 to 5 wt% of eucalyptus CNCs. The nanocrystals were characterized using transmission electron microscopy, whereas the bionanocomposites properties were studied using Fourier transform infrared spectroscopy, tensile measurements, water solubility, swelling behavior, and water activity (aw). The water resistance properties (solubility and swelling behavior) of the nanocomposites were enhanced with the addition of cellulose nanofillers. These results were explained in terms of the high crystallinity of the nanocrystals and the formation of a rigid network with the nanofillers, which provide physical barriers to the permeation of water within the hydrophilic cassava matrix. The addition of CNCs in the bionanocomposites decreases aw linearly, reaching values below 0.5 (for CNCs concentration higher than 4 wt%), a reference value for no microbial proliferation for food product design. The presence of small concentrations of CNCs (0.1–0.3 wt%) also effectively increased the maximum tensile strength (more than 90%) and elastic modulus (more than 400%), indicating the formation of a suitable percolation network in this concentration range. Because the cellulose nanofillers enhanced the mechanical and water stability properties of the nanocomposites, the obtained results in this work may be applied to the development of biodegradable packaging or coatings to enhance shelf life of food products. Practical Application: The main drawbacks of using starch-based polymers as packaging or coating in the food industry are their low mechanical properties and inherent water sensitivity. This study demonstrates that cellulose nanocrystals can be used to: (i) obtain better mechanical properties (increasing the tensile strength and modulus more than 90% and 400%, respectively; (ii) enhance the water stability and (iii) water activity of starch-based films. These results indicate that the obtained environmentally friendly nanocomposites in this work can be used to the development of films or coatings to enhance the shelf life of food products.

Effect of Roasting Conditions on Color and Volatile Profile Including HMF Level in Sweet Almonds (Prunus dulcis)

Abstract: Microwave, oven, and oil roasting of almonds were used to promote almond flavor and color formation. Raw pasteurized almonds were roasted in a microwave for 1 to 3 min, in an oven at 177 °C for 5, 10, 15, and 20 min; and at 135 and 163 °C for 20 min, and in oil at 135, 163, and 177 °C for 5 min and 177 °C for 10 min. Volatile compounds were quantified in the headspace of ground almonds, both raw and roasted, by selected ion flow tube mass spectrometry. Strong correlations were found between L value, chroma, and 5-(hydroxy methyl)-2- furfural; and were independent of roasting method. Raw almonds had lower concentrations of most volatiles than roasted almonds. Conditions that produced color equivalent to commercial samples were 2 min in the microwave, 5 min at 177 °C in the oven, and 5 min at 135 °C in oil. Microwave heating produced higher levels of most volatiles than oven and oil roasting at commercial color. Sensory evaluation indicated that microwave-roasted almonds had the strongest aroma and were the most preferred. Oil-roasted almonds showed significantly lower levels of volatiles than other methods, likely due to loss of these volatiles into the oil. Alcohols such as benzyl alcohols and strecker aldehydes including benzaldehyde and methional were at higher concentrations than other volatiles in roasted almonds. The oxidation of lipids to form alkanals such as nonanal and degradation of sugars to form furan type compounds was also observed. The Maillard reaction contributed to the formation of more of the total volatiles in almonds than the lipid oxidation reaction. Practical Application: The level of 5-(hydroxy methyl)-2- furfural (HMF), color, volatile profile, and sensory perception can be used to develop the best roasting method, time, and temperature for almonds. The rate of color development and the production of volatiles differ under different roasting conditions. Based on the color, volatile, and sensory assessments of the 3 almonds, the use of microwave technology as a process for roasting almonds reduces processing time and leads to an almond product with better flavor than oven or oil roasting.

Effect of Molecular Weight, Acid, and Plasticizer on the Physicochemical and Antibacterial Properties of β‐Chitosan Based Films

Abstract: Effects of chitosan molecular weight (1815 and 366 kDa), type of acid (1% acetic, formic, and propionic acid, or 0.5% lactic acid) and plasticizer (0, 25% glycerol or sorbital w/w chitosan) on the mechanical, water barrier, and antibacterial properties of β-chitosan films were investigated. Tensile strength (TS) of high molecular weight (Hw) films was 53% higher than that of low molecular weight (Lw) ones, acetate, and propionate films had the highest TS (43 and 40 MPa) among tested acids, and plasticizer-reduced film TS 34%. Film elongation at break (EL) was higher in Hw films than in Lw ones, in which formate and acetate films were the highest (9% and 8%, respectively), and plasticizer increased the film EL 128%. Molecular weight of chitosan did not influence water vapor permeability (WVP) of the films. Acetate and propionate films had lower WVP than other acid types of films, and plasticizer increased film WVP about 35%. No difference was found between glycerol and sorbitol films in terms of film mechanical and water barrier properties. Lw β-chitosan films showed significant antibacterial activity against E. coli and L. innocua. This study demonstrated that β-chitosan films are compatible to α-chitosan films in physicochemical properties and antibacterial activity, yet with simple sample preparation.

Characterization of ergocalciferol loaded solid lipid nanoparticles.

Abstract: The use of solid lipid nanoparticles (SLNs) is a technique that has been widely used in the pharmaceutical industry for the last 2 decades and has become of increasing interest to food scientists due to its potential for encapsulation and controlled release. Ergocalciferol (vitamin D2) is a bioactive compound whose deficiency may lead to rickets in children and osteomalacia in adults. In this study, ergocalciferol was encapsulated in tripalmitin SLNs stabilized by polysorbate 20 (Tween 20). SLN dispersions (5% w/w) were prepared by hot homogenization technique using a nozzle-type high-pressure homogenizer. Ergocalciferol at 0%, 5%, 10%, 15%, and 20% (w/w of lipid) was dissolved in the molten lipid at 80 °C, mixed with a 5% (w/w) aqueous solution of polysorbate 20 and homogenized at 138 MPa at 80 °C. Particle size, thermal properties, and microstructure were evaluated by dynamic light scattering (DLS), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) respectively. As the proportion of ergocalciferol in the SLN increased from 0% to 20%, the Z-average values of the particles gradually decreased (P≤ 0.05) from approximately 120 nm to approximately 65 nm. DSC analysis of freeze dried SLN samples showed gradual decrease in enthalpies of fusion and crystallization for stable β-subcell whereas for SLN dispersions, the enthalpy of fusion of unstable α-subcell crystal increased with increased ergocalciferol loading. The TEM images of the ergocalciferol loaded SLN samples showed the presence of spherical as well as rod-shaped nanoparticles. It was also observed that the turbidity of the SLN dispersions reduced noticeably with increased ergocalciferol loading. This finding could be useful in terms of fortification of clear juices with ergocalciferol. Practical Application: Solid lipid nanoparticles (SLNs) were used in this study to encapsulate vitamin D2, a vitamin important for bone health. It was found that as the concentration of vitamin D2 increased in the lipid phase of SLN dispersion, the clarity of the dispersion increased. Also, with increased vitamin D2 concentration, the stability of lipid crystal structure was affected in a way that indicates higher capacity of lipid to incorporate the vitamin molecules and hence to protect them better from oxygen and light. This vitamin loaded SLNs may offer alternatives to milk and margarine as a source of vitamin D.

Phenolic antioxidants in some Vigna species of legumes and their distinct inhibitory effects on α-glucosidase and pancreatic lipase activities.

Abstract: Phenolic extracts of 4 Vigna species of legumes (mung bean, moth bean, and black and red varieties of adzuki beans) were evaluated for phenolic contents, antioxidant activities, and inhibitory properties against α-glucosidase and pancreatic lipase. Results showed that adzuki bean varieties contain higher phenolic indexes than mung bean and moth beans. Adzuki bean (black) variety was found to be the most active 2,2´-diphenyl-1-picrylhydrazyl and superoxide anion scavenger. However, the hydrogen peroxide scavenging and metal chelating abilities were significantly higher in adzuki bean (red) variety. Mung bean exhibited least antioxidant activities in all the methods tested. Phenolic extracts from these legumes also showed distinct variations in the inhibition of enzymes associated with hyperglycemia and hyperlipidemia. Inhibitory activities of all the extracts against lipase were found to be more potent than α-glucosidase. Although, α-glucosidase inhibitory activity was superior in the black variety of adzuki bean (IC50, 26.28 mg/mL), both adzuki bean varieties (black and red) along with moth bean showed strong inhibitory activities on lipase with no significant difference in their IC50 values (7.32 to 9.85 mg/mL). These results suggest that Vigna species of legumes are potential source of antioxidant phenolics and also great sources of strong natural inhibitors for α-glucosidase and lipase activities. This information may help for effective utilization of these legumes as functional food ingredients for promoting health. Practical Application: Vigna species of legumes are good sources of phenolic antioxidants and strong natural inhibitors of enzymes associated with diabetes and obesity. Therefore, utilization of these legumes in the development of functional foods with increased therapeutic value would be a significant step toward health promotion and wellness.