Thermal Reduction of Bacillus spp. in Naturally Contaminated Mesquite Flour with Two Different Water Activities

2020 ◽  
Author(s):  
Xuetong Fan ◽  
Jessica Baik ◽  
Joshua Gurtler
Keyword(s):  
Thermal Resistance ◽  
Bacillus Cereus ◽  
Sugar Content ◽  
Thermal Reduction ◽  
Treatment Temperature ◽  
Heat Sensitivity ◽  
Mesophilic Bacteria ◽  
High Sugar Content ◽  
Bacillus Spp ◽  
D Values

Mesquite flour with endogenous high sugar content is often contaminated with Bacillus cereus.  The purpose of the present study was to evaluate the thermal resistance of Bacillus spp. in naturally contaminated mesquite flour. Flours with and without adjusted water activity (aw) were treated at various temperatures (100-140°C) and times (up to 2 h). Total mesophilic bacteria and Bacillus spp. were enumerated using tryptic soy agar and Brilliance Bacillus Cereus Agar media, respectively. Results revealed that naturally contaminated Bacillus spp. and other mesophilic bacteria in mesquite flour (aw=0.34) were highly resistant to heat. To reduce the initial populations (4.75 log CFU/g) of Bacillus spp. to non-detectable levels (<1.18 log CFU/g), thermal treatments of 120°C for 2 h were required. D100°C-values for total mesophilic bacteria were 5.6 fold higher than those of Bacillus spp. With increasing treatment temperature, the D-value between total mesophilic bacteria and B. cereus became smaller. When the aw of flour was adjusted from 0.34 to 0.71, the D-values for Bacillus decreased significantly.  Treatment at 100°C for 1 h reduced Bacillus spp. populations to nondetectable levels.  Our results demonstrate that naturally present Bacillus spp. in flour are highly resistant to heat, while increasing the aw increased their heat sensitivity.  The high thermal resistance of microbes in mesquite flour warrants further investigations.

Toxin production byBacillus cereusin dairy products

1993 ◽  
Vol 60 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Alastair D. Sutherland
Keyword(s):  
Bacillus Cereus ◽  
Dairy Products ◽  
Sugar Content ◽  
Toxin Production ◽  
Low Ph ◽  
Cold Chain ◽  
Chain Growth ◽  
Significant Growth ◽  
High Sugar ◽  
High Sugar Content

SummarySpores of a known toxigenic and psychrotrophic dairy isolate ofBacillus cereus(HRM 44) were unable to grow and produce diarrhoeagenic toxin at 6 °C in creams and dairy-based products. These findings suggest that the production ofB. cereusdiarrhoeagenic toxin is unlikely to occur in creams and dairy-based products maintained within the cold chain. Growth and toxin production were readily demonstrated in creams and some desserts stored at 21 °C. Growth in creams was associated with obvious spoilage. However, in the flavoured desserts, spoilage was not always obvious before significant growth ofB. cereusand toxin production had occurred. Dairy desserts with high sugar content and/or low pH did not support toxin production and these findings are discussed.

Predictive Thermal Inactivation Model for Listeria monocytogenes with Temperature, pH, NaCl, and Sodium Pyrophosphate as Controlling Factors†

1999 ◽  
Vol 62 (9) ◽  
pp. 986-993 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
BRIAN S. EBLEN
Keyword(s):  
Listeria Monocytogenes ◽  
Thermal Resistance ◽  
Predictive Model ◽  
Heating Temperature ◽  
Sodium Pyrophosphate ◽  
Effect Of Temperature ◽  
Plate Count ◽  
Heat Inactivation ◽  
Heat Sensitivity ◽  
D Values

The effects and interactions of heating temperature (55 to 65°C), pH (4 to 8), salt (NaCl; 0 to 6%, wt/vol), and sodium pyrophosphate (SPP; 0 to 0.3%, wt/vol) on the heat inactivation of a four-strain mixture of Listeria monocytogenes in beef gravy were examined. A factorial experimental design comparing 48 combinations of heating temperature, salt concentration, pH value, and SPP content was used. Heating was carried out using a submerged-coil heating apparatus. The recovery medium was plate count agar supplemented with 0.6% yeast extract and 1% sodium pyruvate. Decimal reduction times (D-values) were calculated by fitting a survival model to the data with a curve-fitting program. The D-values were analyzed by second-order response surface regression for temperature, pH, NaCl, and SPP levels. Whereas increasing the NaCl concentration protected L. monocytogenes against the lethal effect of heat, high SPP concentrations increased heat sensitivity. Also, low pH values increased heat sensitivity of L. monocytogenes. The four variables interacted to affect the inactivation of the pathogen. Thermal resistance of L. monocytogenes can be lowered by combining these intrinsic factors. A predictive model that described the combined effect of temperature, pH, NaCl, and SPP levels on thermal resistance of L. monocytogenes was developed. The model can predict D-values for any combination of temperature, pH, NaCl, and SPP that are within the range of those tested. Using this predictive model, food processors should be able to design adequate thermal regimes to eliminate L. monocytogenes in thermally processed foods.

The Influence of Nisin on the Thermal Resistance of Bacillus cereus

2002 ◽  
Vol 65 (2) ◽  
pp. 415-418 ◽  
Author(s):  
THEREZA CHRISTINA VESSONI PENNA ◽  
DANTE AUGUSTO MORAES
Keyword(s):  
Thermal Resistance ◽  
Bacillus Cereus ◽  
Phosphate Buffer ◽  
White Rice ◽  
Water Ph ◽  
The Mean ◽  
D Values ◽  
Rice Water ◽  
D Value

Decimal reduction times (D-values) at cooking and autoclaving temperatures (80 to 120°C) of spores of Bacillus cereus ATCC 1479-8 in rice and milk (13% wt/vol) supplemented with nisin (25 μg/ml) were evaluated. The mean D-values at 97.8°C in cooked white rice, phosphate buffer (pH 7.0), and rice water (pH 6.7) were 3.62, 1.99, and 1.34 min, respectively. From 80 to 100°C, the mean reduction in D-values due to the addition of nisin to milk was 40%. The D-value at 110°C was ~0.86 min for milk (control) and milk with nisin. The z-values ranged from 7.32°C (phosphate buffer) to 10.37°C (milk control).

Heat Resistance of Bacillus cereus Spores: Effects of Milk Constituents and Stabilizing Additives

1999 ◽  
Vol 62 (4) ◽  
pp. 410-413 ◽  
Author(s):  
MARGARITA MAZAS ◽  
MERCEDES LÓPEZ ◽  
SIDONIA MARTÍNEZ ◽  
ANA BERNARDO ◽  
ROBERTO MARTIN
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Sodium Citrate ◽  
Ph Effect ◽  
Skim Milk ◽  
Milk Composition ◽  
Treatment Temperature ◽  
Monopotassium Phosphate ◽  
The Difference ◽  
D Values

Heat resistance of Bacillus cereus spores (ATCC 7004, 4342, and 9818) heated in different types of milk (skim, whole, and concentrated skim milk), skim milk containing stabilizing additives (sodium citrate, monopotassium phosphate, or disodium phosphate, 0.1%), and cream was investigated. Thermal resistance experiments were performed at temperatures within the range of 92 to 115°C under continuous monitoring of pH. For strain 4342 no significant differences (P < 0.05) in D values were detected in any case. For strains 7004 and 9818 higher D values of about 20% were obtained in whole and concentrated skim milk than those calculated in skim milk. From all stabilizing additives tested, only sodium citrate and sodium phosphate increased the heat resistance for strain 9818. However, when the menstruum pH was measured at the treatment temperature, different pH values were found between the heating media. The differences in heat resistance observed could be due to a pH effect rather than to the difference in the substrates in which spores were heated. In contrast, when cream (fat content 20%) was used, lower D values were obtained, especially for strains 7004 and 9818. z values were not significantly modified by the milk composition, with an average z value of 7.95 ± 0.20°C for strain 7004, 7.88 ± 0.10°C for strain 4342, and 9.13 ± 0.16°C for strain 9818.

The Effectiveness of Amoxicillin and Cefalexin in Two Species from Staphylococcus and Bacillus Isolated from Bovine Mastitis in Sudan

2019 ◽  
Author(s):  
Reem Rabie Mohammed Salih
Keyword(s):  
Bacillus Cereus ◽  
Bovine Mastitis ◽  
Bacillus Coagulans ◽  
Staph Aureus ◽  
Milk Samples ◽  
Sensitivity Tests ◽  
Bacillus Spp ◽  
Staphylococcus Spp

In this study 60 milk samples collected from mastitic cows to isolates and identify bacterial agents. The percentage of isolates was as follows: Staphylococcus spp 52%, Bacillus spp 26%, Enteroccocispp 3%; microccus 3%, Nesseria 2%, Branhamella 3%, Clostridium 1%, Bordetella 2%, Enterobacteria 3%, Aeromonas 4%, Fusobacterium 1%. In sensitivity tests used two antibiotics Amoxicillin and Cephalexin against two highest isolates in this study (Staph spp and Bacillus spp and found: Staph. aureus and Staph. hyicus were resistant to Amoxicllin and cephlaxin relatively, Bacillus coagulans and Bacillus cereus were susceptible to Amoxicllin and cephlaxin.

Harvest Field Sizing as a Technique to Remove Undersize French Prunes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 452a-452
Author(s):  
Richard Buchner ◽  
Seeley Mudd ◽  
Bruce Carroll ◽  
Mark Gilles
Keyword(s):  
Sugar Content ◽  
Economic Value ◽  
Market Value ◽  
Dry Weight ◽  
Soluble Solids ◽  
Field Size ◽  
Test Machine ◽  
Test Field ◽  
Marginal Value ◽  
High Sugar Content

Overall profitability is a major goal in successful prune production and a major component in any prune management system. Large prune crops in 1996 and 1997 have stimulated considerable interest in undersize fruit. Undersize prunes currently have marginal value and may represent a net loss because of costs to haul, dry, and to market order payments on low value prunes. One technique to control delivery size is to field size at harvest. Field sizing involves installing size-sorting devices on harvesters, which allow small prunes to fall out while valuable fruit is collected. Field sizing is considered a “risky” strategy because of the potential to remove prunes with economic value. During the 1997 harvest, 21 infield harvest sizing evaluations were made in prune orchards throughout Tehama county. The first evaluation occurred on 12 Aug. 1997, at the start of prune harvest. The final evaluation was done on 5 Sept. 1997, at the tail end of harvest. The objective was to sample throughout the harvest period to test field sizing under various sugar, size, and fruit pressure scenarios. The test machine was 1-inch bar sizer. Of the 21 sample dates, undersize fruit was clearly not marketable in 20 of the 21 samples. Discarded fruit averaged 133 dry count per pound. Only one sample out of 21 may have had market value at 86 dry count per pound. Although small in size, these prunes had very high sugar content contributing to their dry weight. In this evaluation, a 1-inch bar sizer did a good job of separating fruit with and without market value under the 1997 price schedule. As harvest date becomes later and soluble solids increase, the chances of sorting out marketable prunes also increases.

scholarly journals The “Zero Miles Product” Concept Applied to Biofuel Production: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 565
Author(s):  
Nikolaj Kaae Kirk ◽  
Clara Navarrete ◽  
Jakob Ellegaard Juhl ◽  
José Luis Martínez ◽  
Alessandra Procentese
Keyword(s):  
Sugar Content ◽  
Point Of View ◽  
Biofuel Production ◽  
Transport Costs ◽  
Economic Point ◽  
Product Concept ◽  
Energy Demands ◽  
Production Platform ◽  
High Sugar Content

To make biofuel production feasible from an economic point of view, several studies have investigated the main associated bottlenecks of the whole production process through approaches such as the “cradle to grave” approach or the Life Cycle Assessment (LCA) analysis, being the main constrains the feedstock collection and transport. Whilst several feedstocks are interesting because of their high sugar content, very few of them are available all year around and moreover do not require high transportation’ costs. This work aims to investigate if the “zero miles” concept could bring advantages to biofuel production by decreasing all the associated transport costs on a locally established production platform. In particular, a specific case study applied to the Technical University of Denmark (DTU) campus is used as example to investigate the advantages and feasibility of using the spent coffee grounds generated at the main cafeteria for the production of bioethanol on site, which can be subsequently used to (partially) cover the campus’ energy demands.

Seven-year trends in the availability, sugar content and serve size of single-serve non-alcoholic beverages in New Zealand: 2013–2019

2020 ◽  
pp. 1-13
Author(s):  
Teresa Gontijo de Castro ◽  
Helen Eyles ◽  
Cliona Ni Mhurchu ◽  
Leanne Young ◽  
Sally Mackay
Keyword(s):  
New Zealand ◽  
Sugar Content ◽  
Food Composition ◽  
Soft Drinks ◽  
Alcoholic Beverages ◽  
Slight Reduction ◽  
Cross Sectional ◽  
Sweetened Beverages ◽  
Sugary Drinks ◽  
High Sugar Content

Abstract Objective: To assess trends in relative availability, sugar content and serve size of ready-to-drink non-alcoholic beverages available for sale in supermarkets from 2013 to 2019. Design: Repeat cross-sectional surveys. Data on single-serve beverages to be consumed in one sitting were obtained from an updated brand-specific food composition database. Trends in beverages availability and proportions with serve size ≤ 250 ml were assessed by χ2 tests. Sugar content trends were examined using linear regressions. The proportion of beverages exceeding the sugar threshold of the United Kingdom Soft Drinks Industry Levy (SDIL) was assessed. Setting: New Zealand. Results: From 2013 to 2019, there was (i) an increase in the availability of sugar-free/low-sugar beverages (n 25 (8·4 %) to n 75 (19·1 %); P < 0·001) and craft sugar-sweetened soft drinks (n 11 (3·7 %) to n 36 (9·2 %); P < 0·001), and a decrease in availability of fruit/vegetable juices/drinks (n 94 (31·8 %) to n 75 (19·4 %); P < 0·001); (ii) small decreases in sugar content (mean g/100 ml) of sugar-sweetened soft drinks (3·03; 95 % CI 3·77, 2·29); fruit/vegetable juices/drinks (1·08; 95 % CI 2·14, 0·01) and energy drinks (0·98; 95 % CI 1·63, 0·32) and (iii) slight reduction in the proportion of beverages with serve size ≤ 250 ml (21·6 to 18·9 %; P < 0·001). In 2019, most beverages were sugar-sweetened or had naturally occurring sugars (79·1 %) and serve size > 250 ml (81·1 %) and most sugar-sweetened beverages exceeded the SDIL lower benchmark (72·9 %). Conclusions: Most single-serve beverages available for sale in 2019 were sugary drinks with high sugar content and large serve sizes; therefore, changes made across the years were not meaningful for population’s health.

Feasibility of utilizing sweet potato solids in extrusion cooking / Extrusión de pulpa de batata

1997 ◽  
Vol 3 (3) ◽  
pp. 171-174 ◽  
Author(s):  
H.M. Khalil ◽  
B.R. Henry
Keyword(s):  
Moisture Content ◽  
Sweet Potato ◽  
Sugar Content ◽  
Expansion Ratio ◽  
Fractional Factorial ◽  
Snack Food ◽  
Screw Speed ◽  
High Sugar Content ◽  
Feed Moisture ◽  
Best Parameter

A fractional factorial design of four variables at two levels each was employed to assess the feasi bility and best parameter for extruding sweet potato solids (SPS) using a single screw extruder. It was determined that a high expansion ratio is a desired quality factor for this type of snack food, due to its contribution to textural perception. Preliminary trials on extrusion of sweet potato solids as the sole component in the feed resulted in brittle, dense, and burnt extrudate. The high sugar content (65% total sugar) of the sweet potato solids was cited as the cause of these attrib utes, consequently it was necessary to incorporate wheat flour into the feed to provide a starch matrix for expansion and to reduce sugar concentration. The controlled parameters were screw speed, barrel temperature, feed moisture content, and SPS level in the feed. Among all possible combinations of controlled parameters, the highest expansion ratio was obtained at a screw speed of 220 rpm, temperature profile of 110, 105, 115 and 105 °C, 13% feed moisture content, 50% sweet potato solids, and 0.5% leavening agent.

Productivity of binary herbage based on non-traditional forage crops in the Upper Volga region

2021 ◽  
Author(s):  
N. V. Shmeleva ◽  
Keyword(s):  
Species Composition ◽  
Sugar Content ◽  
Field Studies ◽  
Volga Region ◽  
Forage Crops ◽  
High Sugar ◽  
Upper Volga ◽  
High Sugar Content ◽  
The Upper Volga Region

The article presents the results of field studies aimed at expanding the species composition of herbs and the search for adaptive cereals with a high sugar content in the Upper Volga region in 2015-2020.

Sign in / Sign up

Export Citation Format

Share Document