Wk Of Storage Research Articles

Non-Destructive Assessment of Microstructural Changes in Kabuli Chickpeas during Storage

The potential of hyperspectral imaging (HSI) and synchrotron phase-contrast micro computed tomography (SR-µCT) was evaluated to determine changes in chickpea quality during storage. Chickpea samples were stored for 16 wk at different combinations of moisture contents (MC of 9%, 11%, 13%, and 15% wet basis) and temperatures (10 °C, 20 °C, and 30 °C). Hyperspectral imaging was utilized to investigate the overall quality deterioration, and SR-µCT was used to study the microstructural changes during storage. Principal component analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) were used as multivariate data analysis approaches for HSI data. Principal component analysis successfully grouped the samples based on relative humidity (RH) and storage temperatures, and the PLS-DA classification also resulted in reliable accuracy (between 80 and 99%) for RH-based and temperature-based classification. The SR-µCT results revealed that microstructural changes in kernels (9% and 15% MC) were dominant at higher temperatures (above 20 °C) as compared to lower temperatures (10 °C) during storage due to accelerated spoilage at higher temperatures (above 20 °C). Chickpeas which had internal irregularities like cracked endosperm and air spaces before storage were spoiled at lower moisture from 8 wk of storage.

Analysis of Quality and Color Properties according to the Gas Composition (Modified Atmosphere Packaging) of Pork Sous-Vide Ham Preserved in Natural Brine.

The purpose of this study was to analyze whether seawater has positive effects on appearance characteristics, such as CIE a*, and to determine the gas composition concentration that is suitable for maintaining it. Pork hind meat was cured with four types of curing agent for 5 d at 4°C. The different curing agents comprised the control salt, control nitrite pickling salt (CN), treatment brine, and treatment bittern (BT). The cured hams were cooked at 65°C for 4 h and packaged at O2:N2 gas ratios of 7:3, 8:2, and 9:1 for 3 wk. The physicochemical properties were assessed immediately after heating the sample, and the color properties were measured after a 3 wk storage period. Based on the correlation results of the physicochemical properties, BT had a higher curing and cooking yield than the other treatments, owing to its high salinity. Results of color properties for BT (7:3) and CN (8:2) showed similar color CIE L*, CIE a* chroma, and hue angle values. Therefore, BT can be said to be a sous-vide curing agent suitable for preserving the color of ham, and a high nitrogen concentration of 30% helps to maintain the appearance of seawater sous-vide ham.

Photosensitized oxidation of cholesterol and altered oxysterol levels in sour cream: Effects of addition of cucumber pickles

The aim of this research was to examine whether sour cream (18% fat) is an exogenous source of oxysterols and whether it is possible to improve its antioxidative properties and to modulate cholesterol transformation by adding cucumber. To determine whether cucumber modifies the properties of sour cream, fresh cucumber or cucumber pickle (pH 3.3; 1.5% lactic acid) was added in an amount of 20%. The sour cream samples were then stored under light (450 lx, 590 cd, 120 lm) for 3 wk. After storage, the addition of the cucumber pickle increased total mesophilic aerobic bacteria from 7.5 to 9.3 log cfu/g and increased the l-lactic acid content from 6.1 to 9.7 g/L. The total conjugated linoleic acid content in sour cream with cucumber pickle also increased to 4.5 mg/g fat after storage, whereas the cholesterol content decreased to 3.44 g/kg fat. Importantly, with the addition of cucumber pickle, the total content of cholesterol oxidization products (COP) did not change after storage (1.7 mg/kg fat). By contrast, the total COP content in the control sour cream sample increased from 1.7 to 7.3 mg/kg fat over 3 wk of storage. The dominant COP before and after storage was 7β-hydroxycholesterol. Thus, despite exposure to light, adding cucumber pickle to sour cream modulates cholesterol transformation and effectively inhibits the formation of oxysterols.

Gas production by Paucilactobacillus wasatchensis WDCO4 is increased in Cheddar cheese containing sodium gluconate

Paucilactobacillus wasatchensis can use gluconate (GLCN) as well as galactose as an energy source and because sodium GLCN can be added during salting of Cheddar cheese to reduce calcium lactate crystal formation, our primary objective was to determine if the presence of GLCN in cheese is another risk factor for unwanted gas production leading to slits in cheese. A secondary objective was to calculate the amount of CO2 produced during storage and to relate this to the amount of gas-forming substrate that was utilized. Ribose was added to promote growth of Pa. wasatchensis WDC04 (P.waWDC04) to high numbers during storage. Cheddar cheese was made with lactococcal starter culture with addition of P.waWDC04 on 3 separate occasions. After milling, the curd was divided into six 10-kg portions. To the curd was added (A) salt, or salt plus (B) 0.5% galactose + 0.5% ribose (similar to previous studies), (C) 1% sodium GLCN, (D) 1% sodium GLCN + 0.5% ribose, (E) 2% sodium GLCN, (F) 2% sodium GLCN + 0.5% ribose. A vat of cheese without added P.waWDC04 was made using the same milk and a block of cheese used as an additional control. Cheeses were cut into 900-g pieces, vacuum packaged and stored at 12°C for 16 wk. Each month the bags were examined for gas production and cheese sampled and tested for lactose, galactose and GLCN content, and microbial numbers. In the control cheese, P.waWDC04 remained undetected (i.e., <104 cfu/g), whereas in cheeses A, C, and E it increased to 107 cfu/g, and when ribose was included with salting (cheeses B, D, and F) increased to 108 cfu/g. The amount of gas (measured as headspace height or calculated as mmoles of CO2) during 16 wk storage was increased by adding P.waWDC04 into the milk, and by adding galactose or GLCN to the curd. Galactose levels in cheese B were depleted by 12 wk while no other cheeses had residual galactose. Except for cheese D, the other cheeses with GLCN added (C, E and F) showed little decline in GLCN levels until wk 12, even though gas was being produced starting at wk 4. Based on calculations of CO2 in headspace plus CO2 dissolved in cheese, galactose and GLCN added to cheese curd only accounted for about half of total gas production. It is proposed that CO2 was also produced by decarboxylation of amino acids. Although P.waWDC04 does not have all the genes for complete conversion and decarboxylation of the amino acids in cheese, this can be achieved in conjunction with starter culture lactococcal. Adding GLCN to curd can now be considered another confirmed risk factor for unwanted gas production during storage of Cheddar cheese that can lead to slits and cracks in cheese. Putative risk factors now include having a community of bacteria in cheese leading to decarboxylation of amino acids and release of CO2 as well autolysis of the starter culture that would provide a supply of ribose that can promote growth of Pa. wasatchensis.

Effects of roasting on storage degradability and processing suitability of brown rice powder

To screen the best roasting condition for development of new roasted brown rice products, c.f., roasted brown rice slurry, the storage stability and processing suitability of roasted brown rice powder were studied. In this study, roasted brown rice (BR) powders were prepared with different roasting levels of raw, light roast, medium roast and dark roast. Analyses of roasted BR powder's color, degradability (moisture content, water activity, and acid value), antioxidant activity, processing properties (pasting properties and thermal properties) were carried out. Lower L* value and higher a* value was observed with higher roasting levels. Degradability significantly improved in roasted samples and dark roasted sample showed the lowest water content and acid value though water activity value was the most favorable in light roasted sample (0.2<aw <0.4). Furthermore, antioxidant activity became significantly higher in roasted samples and dark roast showed the highest activity even after 4 wk of storage (21.1–25.9%). In terms of processing suitability, the increased pasting temperature and decreased peak viscosity were observed upon roasting. Advantageously, dark roasted sample showed highest cooling and heating stability. Overall, dark roasted sample showed the best storage stability and functionality, thus, selected as an optimal roasting level.

Effects of antimicrobial addition on lipid oxidation of rendered chicken fat.

This study evaluated the effects of antimicrobial acidulant addition on lipid oxidation of rendered chicken fat. Chicken fat was untreated (control) or treated with either sodium bisulfate (SBS) or lactic acid (LA) at 0.5% w/w and incubated for 6 wk at 40 °C. Peroxide value (PV), p-anisidine value (AV), and free fatty acid (FFA) levels were measured at days 0 (D0), 1(D1), 3 (D3), 5 (D5), and 7 (D7), and weeks 2 (W2), 3 (W3), 4 (W4), 5 (W5), and 6 (W6). The FFA level of untreated-control fat was ~7% and remained consistent throughout the incubation until W6 (~8.5%; P < 0.05). The FFA values in SBS-treated fat were constant (range 7.25%–8.30%) throughout the incubation, whereas the FFA in LA-treated fat peaked at W5 (9.3%; P < 0.05). For the control fat, PVs were between 0.56 and 0.67 meq/100 g until W1 then declined. For the SBS-treated fat, the PVs remained low and similar to the control with the exception of a slight increase on W4 to 0.38 meqv/100 g (P < 0.05). In the LA-treated fat, the PV was greater than (P < 0.05) the control from W1 and increased to a peak on W5 (2.52 meq/100 g). The AV of control fat averaged 2.12 at D0 and increased through W2. In control and LA-treated fat, the AV values declined slightly thereafter, whereas SBS-treated fat increased (P < 0.05) to 10.28 on W5. This study indicates that when included at antimicrobial effective levels, LA may reduce the shelf-life of chicken fat, but SBS had a minimal effect over 6 wk of storage.

Effects of storage temperature on the quality of eggs coated by cassava starch blended with carboxymethyl cellulose and paraffin wax

A blend of cassava starch (CS), carboxymethyl cellulose (CMC), and paraffin was prepared as a coating material to maintain the quality of eggs during 4 wk of storage at different temperatures. The efficacy of the CS/CMC/paraffin (6/1/0.5% w/v) coating was investigated in terms of the Haugh unit (HU), weight loss, pH, and microbial load at the end of storage. The best egg storage temperature was 4°C, which maintained an HU of grade AA in coated and uncoated eggs for 4 wk. Lower weight loss (2.14%) was observed in coated eggs at 4°C storage than at 30°C storage (3.26%). The pH in the albumen of coated and uncoated eggs at 4°C increased from 6.84 to 6.88 and 7.01 to 7.03, respectively, after 4 wk of storage. No microbes were detected in the coated and uncoated eggs at 4°C. The maximum microbial count was 728 ± 35 cfu/mL in uncoated eggs at 30°C storage. Egg coating prevented microbial contamination of eggs stored at 30°C for 4 wk. The freshness of the eggs did not affect the nutrient content. The egg-coating material effectively maintained egg quality, prevented microbial contamination of eggs, and increased the shelf life of eggs at storage temperatures of 25 and 30°C.

Development of an innovative green coating to reduce egg losses

Coatings based on plant by-products can contribute to the enhancement of raw material by preparing value-added products. In addition, the extension of shelf-life of eggs contributes to the reduction of food losses and decreases the use of refrigeration, energy demand, production costs, and consequently avoid the increase in the price of the final product. The rice protein concentrate (RPC) and plus Brazilian green propolis (GP), were used in the manufacture of coatings used to extend the shelf-life of eggs during storage for 6 ​wk at 20 ​°C. In this regard, some quality parameters of eggs were analyzed in this research. The coatings based on RPC and GP delayed the loss of internal egg quality, since avoided moisture loss through the pores of the eggshell. The weight loss increased ( P ​< ​0.001) during storage and uncoated eggs had the worst weight loss (5.41%) after 6 ​wk of storage and coatings of RPC (4.25%) or GP (4.08%), and RPC ​+ ​GP (4.14%) solutions effectively reduced the weight lost ( P ​< ​0.001). In addition, uncoated eggs had the worst value of HU (58.54), albumen pH (9.51), and yolk index (YI 0.33) after storage ( P ​< ​0.001). Correlations were observed between the quality parameters evaluated. The improvement of the quality attributes showed the potential of using coatings, such as the RPC and GP coatings analyzed in this research. • Eggs stored at room temperature presents fast degradation. • Coatings offer protection, increase shelf-life, and reducing egg waste. • A new green coating for eggs was developed. • Rice protein and green propolis coating is a new method to extend shelf-life.

Short communication: Influence of intramuscular injection of vitamin B12 in early-lactation dairy cows on Mozzarella cheese quality and vitamin B12 stability

The current study explored the effect of intramuscular injection of vitamin B12 (VB12) in early-lactation dairy cows on subsequent low-moisture part-skim Mozzarella cheese quality and VB12 levels during cheese processing and storage. Twenty-four peripartum dairy cows were blocked based on parity and milk yield and randomly assigned into 2 treatments: basal diet (CON) and basal diet with an intramuscular injection of 10 mg of VB12 per cow per week (VB12). Raw milk was collected to determine VB12 content and then used to make low-moisture part-skim Mozzarella cheese 8 wk after injection. The VB12 content of raw milk and cheese was determined using ultra-performance liquid chromatography coupled with tandem mass spectrometry. We found that VB12 content was significantly increased in milk (15.43 vs. 3.30 ng/mL) and fresh cheese (3.72 ng/g vs. undetectable) from the VB12 group compared with the CON group. However, approximately 70% of VB12 was lost in the whey during cheese making, and no VB12 was detectable in either cheese treatment after 8 wk of storage. Furthermore, no significant differences were observed in fat and protein contents in the cheese between the 2 groups. For cheese color, the b* value increased and the a* value decreased slightly in fresh VB12 cheese. Functional properties of stretchability, flowability, and meltability of VB12 cheese were initially comparable to that of CON cheese, but higher flowability and meltability was observed in VB12 cheese after 8 wk of storage. In summary, intramuscular injection of VB12 in early-lactation dairy cows increases the content of VB12 in milk and fresh cheese with no adverse effect on cheese quality, but substantial VB12 is lost during cheesemaking and declines rapidly during storage.

Storage stability and in vitro digestion of microencapsulated powder containing fermented noni juice and probiotics

Microencapsulation of fermented noni juice (FNJ) with probiotics is a challenge due to the presence of antibacterial compounds, high levels of organic acids as well as the low pH of the juice. This study aimed to fortify FNJ with Lactobacillus plantarum P8 (LP) and Lactobacillus rhamnosus GG (LGG) using freeze drying, by exploring the possibility of retaining high cell survival rates in the dried powders after drying, during storage and with simulated gastrointestinal (SGI) digestion conditions. Two approaches were studied: 1) drying of the FNJ with bacterial cells simultaneously (powder A); and 2) drying of the FNJ and bacterial cells separately followed by grinding and mixing of the powders (powder B). Both approaches gave powders with high viability (≥9 log CFU/g) of microencapsulated LP and LGG. However, comparing both powder samples, the survival rates of LP and LGG in powder B was significantly higher. After a 7 wk storage at 4 °C, both bacterial strains in powder A showed significant reductions in their viabilities compared to in powder B. The SGI results showed significant lower viable cell counts for both bacteria strains in powder A. After SGI, the viability of bacterial cells in powder B was >7 log CFU/g, higher than the recommended minimal viable probiotics cell concentration according to the US FDA. Between the two strains, LP had a higher survival rate in pure FNJ and a better tolerance toward bile salts (1.2%, w/v). This research showed that fortification of FNJ with a suitable Lactobacillus could be achieved using freeze drying microencapsulation.

Image‐based phenotyping and genetic analysis of potato skin set and color

AbstractImage‐based phenotyping offers new opportunities for fast, objective, and reliable measurement for breeding and genetics research. In the current study, image analysis was used to quantify potato (Solanum tuberosum L.) skin color and skin set, which are critical for the marketability of new varieties. A set of 15 red potato varieties and advanced breeding lines was evaluated over 2 yr at a single location, with two harvest times in the second year. After mechanical harvest and grading, seven to eight representative tubers per plot were photographed, and the photos were analyzed with ImageJ to measure skinning (as percentage surface area) and skin color using the hue, chroma, and lightness (HCL) representation. The plot‐based heritability was consistently high (&gt; .77) across traits and environments; the genetic correlation between environments was also high, ranging from .81–.98. Significant increases in lightness and chroma, as well as a decrease in skinning, were observed at the late compared with early harvest, whereas the opposite trends for color were observed after 6 wk of storage. The three color traits were unexpectedly collinear in this study, with the first principal component explaining 86% of the variation. This result may reflect the physiology of red color in potato, but the highly selected nature of the 15 genotypes may also be a factor. Image‐based phenotyping offers new opportunities to advance genetic gain and understanding for tuber appearance traits that have been difficult to precisely measure in the past.

Effects of rice protein coating enriched with essential oils on internal quality and shelf life of eggs during room temperature storage

The effectiveness of rice protein coatings enriched with essential oils on maintaining interior quality of fresh eggs was evaluated during storage at 20°C for 6 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, and yolk index (YI) in uncoated eggs (control treatment) and eggs coated with rice protein concentrate at 8% enriched or not with different essential oils (1%): tea tree (Melaleuca alternifolia), copaíba (Copaifera langsdorffii), or thymo (Thymus vulgaris). The HU and YI were higher in coated eggs (P < 0.001). Data were submitted to variance analysis, and the statistical models included the effects of treatments (coating types), storage periods (weeks), and interaction (treatments by storage periods). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (5.43%), whereas coatings of rice protein alone (4.23%) or enriched with tea tree (4.10%), copaíba (3.90%), and thymo (4.08%) solutions were effective in preventing weight lost (P < 0.001). The coating use preserved the internal quality of the eggs for up to 3 wk longer than uncoated eggs in terms of HU, YI, and pH. Uncoated eggs had the worst (P < 0.001) HU (58.46), albumen pH (9.48), and YI (0.33) after 6 wk of storage. In conclusion, the use of coatings based on rice protein concentrate enriched with different essential oils influences the internal quality of eggs during storage and may be an effective alternative for increasing the shelf life of commercial eggs.

Listeria monocytogenes Control using Clean-Label Ingredients

ObjectivesWorld’s largest outbreak of listeriosis in South Africa last year, remind us that Listeria monocytogenes contamination and growth is still of major concern in refrigerated RTE meats. The same time customers demand for clean label food safety solutions. Provian NDV, a fermented vinegar based powder, was developed to provide a clean label solution that inhibits Listeria monocytogenes during long term refrigerated storage. This document describes the effect of chemical derived acetates and Provian NDV, a novel vinegar based product, on the inhibition of Listeria monocytogenes in a cooked meat applicationMaterials and MethodsFive treatments of cured deli-style ham were tested. The pork ham contained 72–74% (w/w) moisture, 1.75 ± 0.1% (w/w) salt, and pH 6.2–6.4, 156 mg/kg sodium nitrite and 547 mg/kg sodium erythorbate. The treatments included a control without antimicrobials and different concentrations of a chemically derived acetates (0.5% and 0.75%) and Provian® NDV (0.5%, 0.65%). Cooked products were surface-inoculated with 3-log10 CFU/g of a cocktail of 5 strains of Listeria monocytogenes from the culture collection of Food research institute, Wisconsin University including serotypes 4b, 1/2a, and 1/2b. All strains were isolated from RTE- cooked meat products. Inoculated slices (100 g/package) were vacuum-packaged and stored at 4°C and 7°C for 8 to 12 wk. Per treatment triplicate samples were assayed by enumerating on modified Oxford Agar. One way ANOVA was used to analyze significance, p &lt; 0.05. Except from the triplicate repeat, this study was conducted twice independently (trial 1, 5 treatments in triplicate and trial 2 including same treatments, also in triplicate.)ResultsControl Ham supported &gt; 1 log increase of L. monocytogenes at 4- and 2-weeks storage at 4 and 7°C, respectively. In contrast, hams supplemented with 0.5 or 0.75% chemical acetates or 0.65% Provian® NDV inhibited the Listeria growth for 12 and 8 wk at 4 and 7°C, respectively. Inhibition of Listeria on ham supplemented with 0.5% Provian®NDV was further affected by pH and moisture. Ham supplemented with 0.5% Provian® NDV in the trial 1 (71.5% moisture, pH 6.2) delayed Listeria for 12 wk storage at 4°C, whereas individual samples of trial 1 (72.9% moisture, pH 6.3) supported growth (&gt; 1 log increase) at 8 wk. Similar trends were observed at 7°C. The images below reflect the results of trial 1 only.ConclusionThis study confirms the efficacy of acetates on the inhibition of Listeria monocytogenes. Next, this study shows that a product based on natural fermented vinegar, Provian NDV, has a comparable growth inhibitive action in a cured ready-to eat ham. This illustrates that most relevant serotypes (4b, 1/2b and 1/2a) of Listeria moncytogenes can be controlled using an ingredient based on natural fermented vinegar.Figure 4.

Survivability and oxidative stability of co-microencapsulated L. Plantarum PTCC 1058 and DHA as a juice carrier

Lactobacillus Plantarum PTCC 1058 bacteria and DHA-rich oil were microencapsulated together or individually in an optimized alginate-pectin-gelatin biocomposite hydrogel. The survivability of L. plantarum and oxidative stability of DHA were evaluated using simulated gastrointestinal (SGI) conditions and 4 wk storage in commercial orange juice at 4 and 25 °C. The results showed that the multilayer biocomposite had significant influence on the stability of the microcapsules in terms of survivability of probiotic bacteria and oxidative stability of DHA with SGI conditions and storage at 4 and 25 °C compared to the free cells. Incorporation of probiotic bacteria and DHA showed the synergistic effect of DHA on cell survivability as less cell reduction was observed with co-microcapsules compared to probiotic microcapsules with storage in orange juice at both temperatures. Determination of peroxide values and fatty acid profiles, showed the oxygen barrier potential of the co-microcapsules could provide better stabilization for food matrices.

Effects of rice protein coatings combined or not with propolis on shelf life of eggs.

Although eggs are an excellent protein source, they are a perishable product. Many methods exist to extend shelf life of food and one of them is the use of protein coatings that may be combined with antimicrobial substances, as propolis. The effectiveness of rice protein coatings plus propolis on maintaining interior quality and eggshell breaking strength of fresh eggs was evaluated during storage at 20°C for 6 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, yolk index (YI), shell strength, and scanning electron microscopy in uncoated eggs (control treatment) and eggs coated with rice protein concentrate and propolis at 5 or 10%. The HU and YI were higher in coated eggs (P < 0.001). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (5.39%), whereas rice protein (4.27%) and rice protein plus propolis at 5% (4.11%) and 10% (4.40%) solutions were effective in preventing weight lost (P < 0.001). Uncoated eggs had the worst (P < 0.001) HU (58.47), albumen pH (9.48), and YI (0.33) after 6 wk of storage. The eggs coated with rice protein and rice protein plus propolis presented results with similar intern quality between them during all the storage period. Scanning electron microscopy demonstrated a lower surface porosity in coated eggshell, indicating that the use of the coating may provide a protective barrier against the transfer of gases and moisture. In conclusion rice protein and propolis treatments helped to maintain egg quality for a longer time compared to uncoated eggs. These could be a viable alternative for maintaining the internal quality of fresh eggs during long-term storage at room temperature.

Reliable detection, sequencing, and transfection of foot-and-mouth disease virus RNA from badly preserved vesicular epithelium.

Epithelium or fluid from vesicular lesions are the preferred samples to confirm foot-and-mouth disease virus (FMDV) infection in livestock. A pH-neutral buffered transport medium is recommended for optimal preservation of epithelial samples, but may not be necessary for all circumstances based on the results of our study. Pieces of epithelium were collected from FMDV-infected cattle (isolates O/FRA/1/2001 and A/IRN/22/2015) and stored at room temperature in sealed tubes without any liquid or preservatives. Using RNA extracted from the severely decayed epithelium up to 3 wk after collection, FMDV was successfully detected by RT-rtPCR, and the viral strain was identified by sequencing of capsid protein VP1. Direct isolation of the virus in cell culture was only possible for vesicular material stored for up to 2-5 d, depending on the serotype, but, for both serotypes, infectious virus was recovered by transfection of RNA extracted from epithelium after 3 wk of storage at room temperature. Specialized transport medium will give optimal results, particularly for low-titer samples, but is not required for the reliable detection and characterization of FMDV in highly positive vesicular epithelium by molecular methods.

Effects of Traditional Sauce Type and Storage Time on Quality Characteristics, Shelf-life and Flavor Compounds of Marinated Pork Cooked by Sous Vide Method.

The present study aimed at evaluating effects of traditional sauce type and storage time on shelf-life and flavor compounds of marinated pork cooked by Sous-Vide method. Five different traditional sauces (Meju soy sauce, Brewed soy sauce, Fish-soy sauce, Ishiru fish sauce and Anchovy fish sauce) purchased from Asian countries were used. After marination with the sauces, polyvinylchloride film bags containing the marinated pork samples were cooked using Sous-Vide method for 55°C for 5 h and 60°C for 30 min, and were then stored for 8 wk at 10°C. Results showed that the pork samples marinated with the sauces retarded the growth of total plate counts (TPC) during storage. At 8th wk storage, TPC counts were significantly lower in all samples marinated with the sauces compared to control (p<0.05). Lipid oxidation level was significantly lower in the T2 (Meju soy sauce) and T6 (Anchovy fish sauce) compared to those of T3 (Brewed soy sauce) and T5 (Ishiru fish sauce) or control after 8 wk storage (p>0.05). Forty volatile flavor compounds were detected from the control and marinated samples at 4th wk of storage. The pork marinated with Anchovy fish sauce presented significantly higher amounts of importantly pleasant flavor compounds such as; pyrazines and sulfur-containing compounds than those marinated with other remaining sauces and control. It is concluded that the marination with Anchovy fish sauce partly improved the shelf-life and increased amounts of pleasant flavor compounds of Sous-Vide cooked pork products during storage in comparison to the other remaining sauces.

Rice protein coating in extending the shelf-life of conventional eggs

The effectiveness of rice protein coatings or mineral oil on maintaining interior quality and eggshell breaking strength of fresh eggs was evaluated during storage at 20°C for 8 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, yolk index (YI), shell strength, and scanning electron microscopy in uncoated eggs (control treatment) and eggs coated with mineral oil or rice protein concentrate at 5, 10, or 15%. The HU and YI were higher in coated eggs (P < 0.001). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (8.28%), whereas mineral oil (0.87%) and rice protein at 5% (5.60%), 10% (5.45%), 15% (5.54%) solutions were effective in preventing weight lost (P < 0.001). The use of the coatings preserved the internal quality of the eggs for up to 4 wk longer than uncoated eggs (HU, YI, and pH). Uncoated eggs had the worst (P < 0.001) HU (54.45), albumen pH (9.18), and YI (0.28) after 8 wk of storage. Among the coated eggs, the mineral oil had the best values of HU (70.54), pH (8.48), and YI (0.35) after storage. The eggs coated with 5, 10, and 15% of rice protein presented results with similar intern quality between them and intermediary quality in relation to the others treatments during all the storage period. Scanning electron microscopy demonstrated a lower surface porosity in coated eggshell, indicating that the use of the coating may provide a protective barrier against the transfer of gases and moisture. In conclusion, the use of coatings based on rice protein concentrate or mineral oil influences the internal quality of eggs during storage and may be an effective alternative for increasing the shelf-life of commercial eggs.

Short communication: Influence of an aqueous myrrh suspension on yogurt culture bacteria over yogurt shelf life

Myrrh is an essential oil and natural flavoring approved by the US Food and Drug Administration, and it has antibacterial and antifungal activity against pathogens. Our objective was to determine the effect of an aqueous myrrh suspension on Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus counts in peptone solution and yogurt, as well as pH and titratable acidity of yogurt during 5 wk of storage at 1 to 4°C. The myrrh suspension (10% wt/vol) was prepared and incorporated into a pure culture dilution in peptone and into yogurt mix at a 1% (vol/vol) level. A control with no myrrh was also prepared, and 3 replications were conducted. Streptococcus thermophilus were enumerated using Streptococcus thermophilus agar with aerobic incubation at 37°C for 24 h, and Lactobacillus delbrueckii ssp. bulgaricus were enumerated using de Man, Rogosa, and Sharpe agar adjusted to pH 5.2, with anaerobic incubation at 43°C for 72 h. During the 8-h period after inoculation, S. thermophilus and L. delbrueckii ssp. bulgaricus counts in peptone solution at 37°C and 43°C, respectively, were not significantly different in the presence or absence of the aqueous myrrh suspension. Counts of S. thermophilus in yogurt containing myrrh (mean ± SD; 4.96 ± 0.58 log cfu/mL) were not significantly different from those in the control yogurt (4.87 ± 0.39 log cfu/mL). The log counts for L. delbrueckii ssp. bulgaricus in yogurt containing myrrh (5.04 ± 1.44 log cfu/mL) and those of the control (5.52 ± 1.81 log cfu/mL) did not differ, and the counts remained within 1 log of each other throughout 5 wk of storage. The pH of the yogurts containing the aqueous myrrh suspension was not significantly different from that of the control yogurts, and their pH values were within 0.1 pH unit of each other in any given week. Titratable acidity values remained steady around 1.1 to 1.2% lactic acid for both yogurt types throughout the storage period, with no significant differences between them. Yogurt culture bacteria can survive in the presence of a myrrh suspension in yogurt with no significant change in pH or titratable acidity. Therefore, it may be beneficial to add an aqueous myrrh suspension to yogurt.

Use of Ethyl Formate Fumigation to Control Adult Bean Thrips in Navel Oranges.

Shipments of California Navel oranges (Citrus sinensis) (Osbeck)) that are found to be infested with adult bean thrips (Caliothrips fasciatus (Pergande) (Thysanoptera: Thripidae)) upon arrival in Australia either undergo mandatory fumigation with methyl bromide (MeBr) to kill the thrips or are refused entry. Ethyl formate (EtF) mixed with carbon dioxide (CO₂) is an effective fumigant for control of various arthropods including but not limited to, thrips, aphids, Pacific spider mites, California red scale, and omnivorous leaf rollers. Dose-mortality curves at 5°C, 10°C, and 15°C were developed for control of adult bean thrips using EtF plus CO₂, with 5°C being more effective. In further testing, the efficacy of EtF plus CO₂ against adult bean thrips in Navel oranges and the impact on fruit quality after fumigation followed by 5 wk of storage at 5°C and shelf life at 20°C was determined. Fruit fumigated with 31 g/m3 EtF plus CO₂ at 5°C for 1 h showed no difference in quality compared with untreated control fruit. Ethyl formate plus CO₂ fumigation efficacy was confirmed in a 27.32 m3 sea freight container with eight pallets of packed Navel oranges (load factor 28.69%) and 10,000-15,000 adult bean thrips in each of three replications. Complete control of adult bean thrips was achieved with no negative effects on fruit quality.