scholarly journals Pre-treatment dips to enhance the removal of apple leafcurling midge from apples using high pressure washing

2017 ◽  
Vol 70 ◽  
pp. 315
Author(s):  
N.E.M. Page-Weir ◽  
L.E. Jamieson ◽  
A.J. Hawthorne ◽  
S.P. Redpath ◽  
A. Chhagen ◽  
...  

The presence of apple leafcurling midge (ALCM) on apples is of concern for many of New Zealand’s export apple markets. High pressure washing (HPW) systems have been implemented in export packhouses to reduce the risks associated with various pests; however, higher removal rates of ALCM are required to improve access to challenging markets. A range of pre-treatment dips to improve ALCM removal efficacy when applied before HPW were tested, and the impact of these pre-treatment dips on pest viability determined. Removal of ALCM cocoons by HPW alone was 41%, compared with pre- treatments of hot water at 51˚C (66%), Saturate® (58%), Prospect oil® (57%), malic acid (53%), citric acid (48%), lactic acid (46%), acetic acid (39%), HarvestCide® (37%) or sodium bicarbonate (37%). However, only the hot-water treatment significantly enhanced removal compared with HPW alone. In a second trial, removal of ALCM cocoons with HPW was 69% and hot water + UV-C increased removal to 76%, although this difference was not statistically significant. Overall, none of the pre-treatment dips was found to reduce ALCM viability significantly compared with HPW alone.

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 78 ◽  
Author(s):  
Guido Rux ◽  
Efecan Efe ◽  
Christian Ulrichs ◽  
Susanne Huyskens-Keil ◽  
Karin Hassenberg ◽  
...  

In practice, fresh-cut fruit and fruit salads are currently stored submerged in sugar syrup (approx. 20%) to prevent browning, to slow down physiological processes and to extend shelf life. To minimize browning and microbial spoilage, slices may also be dipped in a citric acid/ascorbic acid solution for 5 min before storage in sugar syrup. To prevent the use of chemicals in organic production, short-term (30 s) hot-water treatment (sHWT) may be an alternative for gentle sanitation. Currently, profound knowledge on the impact of both sugar solution and sHWT on aroma and physiological properties of immersed fresh-cuts is lacking. Aroma is a very important aspect of fruit quality and generated by a great variety of volatile organic compounds (VOCs). Thus, potential interactive effects of sHWT and sugar syrup storage on quality of fresh-cut apple slices were evaluated, focusing on processing-induced changes in VOCs profiles. Intact ’Braeburn’ apples were sHW-treated at 55 °C and 65 °C for 30 s, sliced, partially treated with a commercial ascorbic/citric acid solution and slices stored in sugar syrup at 4 °C up to 13 days. Volatile emission, respiration and ethylene release were measured on storage days 5, 10 and 13. The impact of sHWT on VOCs was low while immersion and storage in sugar syrup had a much higher influence on aroma. sHWT did not negatively affect aroma quality of products and may replace acid dipping.


2000 ◽  
Vol 42 (9) ◽  
pp. 235-241 ◽  
Author(s):  
M. Barjenbruch ◽  
H. Hoffmann ◽  
O. Kopplow ◽  
J. Tränckner

Several reasons can lead to the emergence of foam in digesting tanks, for instance overloading or the impact of hydrophobic substances. Furthermore, the foaming is in regular periods going together with the emergence of filamentous microorganisms. Up to now, several strategies to avoid foaming have been tested out (for instance reduction of the sludge load in the activated sludge stage, lowering of the sludge level in the digestion tank, dosage of anti foaming agents), but these have been done relatively unsystematically and with more or less success. For our contribution, laboratory-scale digestion tests were run to analyse mechanical and thermal pre-treatment methods for the destruction of the surplus sludge. Whereas the disintegration by a high pressure homogeniser did only achieve a low reduction of the foam phase, the thermal pre-treatment at 121°C made for an effective subduing of the foam emergence. Both methods allowed for a cutting up of the filaments, but only the heating up effected the reduction of the hydrophobic substances; thus, the foaming is possibly caused by them.


1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).


2012 ◽  
Vol 78 (15) ◽  
pp. 5395-5405 ◽  
Author(s):  
Gilberto Vinícius de Melo Pereira ◽  
Maria Gabriela da Cruz Pedrozo Miguel ◽  
Cíntia Lacerda Ramos ◽  
Rosane Freitas Schwan

ABSTRACTSpontaneous cocoa bean fermentations performed under bench- and pilot-scale conditions were studied using an integrated microbiological approach with culture-dependent and culture-independent techniques, as well as analyses of target metabolites from both cocoa pulp and cotyledons. Both fermentation ecosystems reached equilibrium through a two-phase process, starting with the simultaneous growth of the yeasts (withSaccharomyces cerevisiaeas the dominant species) and lactic acid bacteria (LAB) (Lactobacillus fermentumandLactobacillus plantarumwere the dominant species), which were gradually replaced by the acetic acid bacteria (AAB) (Acetobacter tropicaliswas the dominant species). In both processes, a sequence of substrate consumption (sucrose, glucose, fructose, and citric acid) and metabolite production kinetics (ethanol, lactic acid, and acetic acid) similar to that of previous, larger-scale fermentation experiments was observed. The technological potential of yeast, LAB, and AAB isolates was evaluated using a polyphasic study that included the measurement of stress-tolerant growth and fermentation kinetic parameters in cocoa pulp media. Overall, strainsL. fermentumUFLA CHBE8.12 (citric acid fermenting, lactic acid producing, and tolerant to heat, acid, lactic acid, and ethanol),S. cerevisiaeUFLA CHYC7.04 (ethanol producing and tolerant to acid, heat, and ethanol), andAcetobacter tropicalisUFLA CHBE16.01 (ethanol and lactic acid oxidizing, acetic acid producing, and tolerant to acid, heat, acetic acid, and ethanol) were selected to form a cocktail starter culture that should lead to better-controlled and more-reliable cocoa bean fermentation processes.


2019 ◽  
Vol 31 (9) ◽  
pp. 095204 ◽  
Author(s):  
Khalidah H Al-Mayalee ◽  
Emad Badraddin ◽  
Fumiya Watanabe ◽  
Tansel Karabacak

2012 ◽  
pp. 1305-1311 ◽  
Author(s):  
F.E. Loayza ◽  
J.K. Brecht ◽  
A. Plotto ◽  
E.A. Baldwin ◽  
J. Bai

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 49-50
Author(s):  
Youngji Rho ◽  
Rob Patterson ◽  
Elijah Kiarie

Abstract We investigated the impact of steeping corn DDGS over 72 h with or without fiber degrading enzymes (FDE) and protease (PRO) on concentration of sugar, acetic and lactic acid, and pH. The concentration of crude fat, CP, NDF and ADF in DDGS sample was 8.6, 30.8, 36.1, 12.2% DM, respectively. Treatments were: 1) DDGS steeped without enzymes (Control), 2) DDGS steeped with FDE (FDE), 3) DDGS steeped with protease (PRO), 4) DDGS steeped with combination (FDEPRO). Enzymes were added at 1% of DDGS. Briefly, 50g of DDGS was mixed with 500-mL water with or without enzymes in sterile plastic bottles and steeped for 0, 12, 24, 48 and 72-h at 37℃ with continuous agitation. Samples were aliquoted to individual bottle for each timepoint. At each time point, bottles were pulled out from the incubator for pH measurements and liquid medium supernatant for sugars and acids. Highest arabinose, xylose and glucose was observed at 12 and 24 h, followed by decrease at 48 and 72 h. At 12 h, arabinose was higher (P < 0.05) for FDE and FDEPRO than control. The highest xylose and glucose was seen at 12 h for PRO, FDE and FDEPRO while control was highest at 24 h. Acetic acid and lactic acid increased over time. At 72 h, FEDPRO had highest acetic acid compared to control and PRO, while lactic acid was highest for FDE and FDPRO compared with (P < 0.0001) control and PRO. The pH decreased (P < 0.05) over time for all treatments. At 72 h, FDE had lowest pH followed by FDEPRO, PRO and control (P < .0001). Overall, arabinose, xylose and glucose increased to a certain timepoint and decreased, while lactic and acetic acid increased over time, subsequently leading to lowest pH at 72 h. In conclusion, FDE increased concentration of sugars and acids in steeped DDGS whereas PRO had no effect.


2003 ◽  
Vol 66 (6) ◽  
pp. 985-992 ◽  
Author(s):  
J. S. IKEDA ◽  
J. SAMELIS ◽  
P. A. KENDALL ◽  
G. C. SMITH ◽  
J. N. SOFOS

The objective of this study was to evaluate the survival and growth of acid-adapted and nonadapted Listeria monocytogenes inoculated onto fresh beef subsequently treated with acid or nonacid solutions. Beef slices (2.5 by 5 by 1 cm) from top rounds were inoculated with acid-adapted or nonadapted L. monocytogenes (4.6 to 5.0 log CFU/cm2) and either left untreated (control) or dipped for 30 s in water at 55°C, water at 75°C, 2% lactic acid at 55°C, or 2% acetic acid at 55°C. The beef slices were vacuum packaged and stored at 4 or 10°C and were analyzed after 0, 7, 14, 21, and 28 days of storage. Dipping in 75°C water, lactic acid, and acetic acid resulted in immediate pathogen reductions of 1.4 to 2.0, 1.8 to 2.6, and 1.4 to 2.4 log CFU/cm2, respectively. After storage at 10°C for 28 days, populations of L. monocytogenes on meat treated with 55°C water increased by ca. 1.6 to 1.8 log CFU/cm2. The pathogen remained at low population levels (1.6 to 2.8 log CFU/cm2) on acid-treated meat, whereas populations on meat treated with 75°C water increased rapidly, reaching levels of 3.6 to 4.6 log CFU/cm2 by day 14. During storage at 4°C, there was no growth of the pathogen for at least 21 days in samples treated with 55 and 75°C water, and periods of no growth were longer for acid-treated samples. There were no differences between acid-adapted and nonadapted organisms across treatments with respect to survival or growth. In conclusion, the dipping of meat inoculated with L. monocytogenes into acid solutions reduced and then inhibited the growth of the pathogen during storage at 4 and 10°C, while dipping in hot water allowed growth despite initial reductions in pathogen contamination. The results of this study indicate a residual activity of acid-based decontamination treatments compared with water-based treatments for refrigerated (4°C) or temperature-abused (10°C) lean beef tissue in vacuum packages, and these results also indicate that this activity may not be counteracted by prior acid adaptation of L. monocytogenes.


1997 ◽  
Vol 1997 (1) ◽  
pp. 679-686 ◽  
Author(s):  
Jonathan P. Houghton ◽  
Robert H. Gilmour ◽  
Dennis C. Lees ◽  
William B. Driskell ◽  
Sandra C. Lindstrom ◽  
...  

ABSTRACT Eight years of quantitative biological and chemical data have been analyzed for trends in recovery of biota inhabiting beaches in Prince William Sound following the 1989 Exxon Valdez oil spill and subsequent shoreline treatments. Sampling has focused on biota at sheltered rocky and mixed-soft sites subjected to three degrees of disturbance (unoiled, oiled but not hot-water washed, and oiled/hot-water washed). Only epibiota on sheltered rocky habitats are covered in this paper. The majority of community dominants survived 1989 on oiled rocky shores that were not high-pressure, hot-water washed. These areas appeared to be nearly completely recovered by 1991, although subsequent monitoring has revealed oscillations in species abundances that exceed those on unoiled beaches. Hot-water treatments used in 1989 had severe short-term impacts on intertidal epibenthos. Some high-pressure, hot-water-treated rocky shores stripped of biota in 1989 showed very slow colonization through 1995; other areas that appeared to be nearly recovered in 1992 suffered severe declines in dominant taxa in 1995. The dominant age class of rockweed, which began life following hot-water treatment, matured in 1993 and died off in 1994 and 1995, resulting in declines of associated fauna. A new cycle of rockweed colonization has begun, and some recovery of rockweed and associated fauna was observed in 1996.


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