Influence of air equilibration time, sampling techniques, and storage temperature on enzymatic starch availability of steam-flaked corn

Abstract Measuring enzymatic starch availability is commonly used as a quality control method to ensure steam-flaked corn manufacturing consistency in commercial cattle feeding operations. However, starch availability estimates can be variable. We conducted five experiments to evaluate factors influencing starch availability estimates of steam-flaked corn. In Exp. 1, sample handling methods were evaluated. Sifted flakes were immediately placed into a plastic bag, air equilibrated for 240 min, oven-dried, or freeze-dried. Directly oven-drying samples at 55ºC decreased (P < 0.01) starch availability compared to other sample handling methods. In Exp. 2, sifted flakes were air equilibrated for 0, 15, 30, 60, 120, or 240 min. Air equilibration time did not influence (P ≥ 0.54) starch availability. In Exp. 3, samples were evaluated for effects of sifting through a 4-mm screen (flakes + fines vs. sifted flakes) and air equilibration time (0 vs. 240 min). Both sifting steam-flaked corn samples and air equilibration for 240 min increased starch availability (P < 0.01 and P = 0.02, respectively). In Exp. 4, we evaluated the effects of air equilibration time (0 vs. 240 min) on the two sifted portions (sifted flakes vs. sifted fines). There was an air equilibration time × sifted particle size interaction for starch availability because air equilibration time increased (P < 0.01) starch availability of sifted fines but did not influence starch availability of sifted flakes. Concentrations of crude protein, soluble crude protein, neutral and acid detergent fiber, ether extract, and acid-hydrolyzed fat, Ca, P, K, Mg, S, Fe, Zn, Mg, and Cu were greater (P < 0.01) for sifted fines compared to sifted flakes. Starch availability and total starch concentration were greater (P < 0.01) for sifted flakes compared to sifted fines. In Exp. 5, effects of air equilibration time (0 vs. 240 min) and storage temperature (23ºC vs. 55 ºC) on flakes + fines were evaluated. Storage of flakes + fines in heat-sealed foil bags at 55ºC for 3-d decreased (P < 0.01) starch availability by 40.7%. Sifted flakes contained less moisture, greater total starch concentrations, and greater starch availability than sifted fines. Moisture, sifting, air equilibration time, and storage temperature influence starch availability of steam-flaked corn. Adoption of the strategies discussed in the current study will lead to more consistent estimates of starch availability.

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Viability of L. casei during fermentation in soymilk and freeze-dried soymilk; effect of cryoprotectant, rehydration and storage temperature

Macedonian Pharmaceutical Bulletin ◽

10.33320/maced.pharm.bull.2006.52.003 ◽

2006 ◽

Vol 52 ◽

pp. 17-24

Author(s):

Lela Acevska ◽

Kristina Mladenovska ◽

Tanja Petreska Ivanovska ◽

Maja Jurhar Pavlova ◽

Milena Petrovska ◽

...

Keyword(s):

Freeze Drying ◽

Storage Temperature ◽

Acid Stress ◽

Titratable Acidity ◽

Therapeutic Level ◽

Freeze Dried ◽

Different Temperatures ◽

And Storage

Viability of L. casei during fermentation in soymilk and freeze-dried soymilk; effect of cryoprotectant, rehydration and storage temperature The aim of the work was to investigate the behaviour of L. casei and the effect of sorbitol on its viability during fermentation in soymilk drink. Values for pH, ranging from 6.82 to 3.42 in the soymilk drink without sorbitol and from 6.74 to 3.41 in the drink with sorbitol were noted during 72 h of fermentation at 25oC. The corresponding values for titratable acidity ranged from 0.071% to 0.758% and from 0.073% to 0.761%, respectively. Soymilk was found to support the growth of L. casei with improvement in viability for 0.24 log at the end of fermentation when sorbitol was added. Survival of L. casei and the effectiveness of sorbitol in improving viability during freeze-drying, subsequent rehydration and during a 5-week period of storage under different temperatures were also investigated. After freeze-drying, L. casei exhibited a survival percent of approximately 46%. Sorbitol improved the viability of L. casei by 0.51 log immediately after freeze-drying and by 1.30 log and 0.47 log during five weeks of storage at 25oC and 4oC, respectively. Further study revealed that the freeze-dried fermented soymilk rehydrated at 45oC was optimum for the recovery of L. casei with improvement in recovery for 0.68 log when sorbitol was added. A higher percent of survival was noted when the dried soymilk was stored at 4oC than at 25oC with improved viability at the end of 5 weeks storage for approximately 6 log for drinks with and without sorbitol. Fermented dried soymilk with sorbitol afforded significant tolerance of L. casei to acid stress. Generally, a stable probiotic diary product was prepared in which the concentration of L. casei remained above therapeutic level of 107 cfu/ml.

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Exploring validity of the macro-micro region concept in the state diagram: Browning of raw and freeze-dried banana slices as a function of moisture content and storage temperature

Journal of Food Engineering ◽

10.1016/j.jfoodeng.2017.01.017 ◽

2017 ◽

Vol 203 ◽

pp. 32-40 ◽

Cited By ~ 10

Author(s):

Mohammad Shafiur Rahman ◽

Ghalib Said Al-Saidi

Keyword(s):

Moisture Content ◽

Storage Temperature ◽

State Diagram ◽

The State ◽

Freeze Dried ◽

And Storage

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Effects of Lyophilization and Storage Temperature on Wuchereria bancrofti Antigen Sensitivity and Stability

10.20944/preprints201804.0170.v1 ◽

2018 ◽

Author(s):

Edem Y. Agbozo ◽

Edward Dumashie ◽

Daniel A. Boakye ◽

Dziedzom K. de Souza

Keyword(s):

Storage Temperature ◽

Wuchereria Bancrofti ◽

Rapid Diagnostic Tests ◽

Plasma Samples ◽

Freeze Dried ◽

Duration Of Storage ◽

Control Programmes ◽

Increasing Temperature ◽

And Storage ◽

Blood Spot

Antigen-based rapid diagnostic tests for Lymphatic filariasis do not come with quality control (QC) materials, and research and disease control programmes rely on stored positive plasma samples. This study was undertaken to evaluate the use of freeze-dried Wuchereria bancrofti antigen positive plasma samples to serve as QC materials for LF RDTs. 10 well characterized W. bancrofti positive samples were lyophilized and stored at 4°C, 28°C and 40°C. The samples were evaluated using the Filaria Test Strips before lyophilization and after one and three (3) months of storage. The sensitivity and stability of the lyophilized samples were evaluated. The results revealed a loss of sensitivity and stability with increasing temperature and duration of storage. The results are further discussed in terms of the use of Dried Blood Spot (DBS) in diagnostics studies on LF requiring quantitative assessments, and the need for thoughtful DBS preparation and storage.

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Stability of Vitamins B1, B2, B6 and E in a Fortified Military Freeze-Dried Meal During Extended Storage

Foods ◽

10.3390/foods9010039 ◽

2020 ◽

Vol 9 (1) ◽

pp. 39

Author(s):

Ross Coad ◽

Lan Bui

Keyword(s):

Water Activity ◽

Storage Temperature ◽

Effective Means ◽

Retention Rates ◽

Vitamin Content ◽

Freeze Dried ◽

Colour Changes ◽

C 30 ◽

And Storage

Australian military ration packs contain a variety of processed foods, including some that are fortified with vitamins. In this study, freeze-dried meals, a key component of lightweight patrol ration packs, were fortified at the time of packing by direct addition of a vitamin premix containing vitamins B1, B2, B6 and E. Fortification was at three levels: 50%, 100% and 200% of the recommended vitamin content for military ration packs. Vitamin stability was determined following storage at temperatures of 1 °C, 30 °C and 40 °C for up to 24 months. HPLC methods were used to measure vitamin content; water activity and colour were also determined. Mean 24-month retention rates across all temperatures and fortification levels were 94%, 97%, 86% and 77% for vitamins B1, B2, B6 and E, respectively. Water activity increased with storage temperature, whereas colour changes due to fortification and storage temperature were at the threshold of visual detection. Fortification of freeze-dried meals would be an effective means of improving the quality of light weight military ration packs by addressing shortfalls in vitamin levels.

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Effect of polymers and storage temperature on the stability of freeze-dried lactic acid bacteria

Food Research International ◽

10.1016/0963-9969(95)00050-x ◽

1996 ◽

Vol 29 (5-6) ◽

pp. 555-562 ◽

Cited By ~ 84

Author(s):

Claude P. Champagne ◽

Francine Mondou ◽

Yves Raymond ◽

Denis Roy

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Storage Temperature ◽

Freeze Dried ◽

The Stability ◽

And Storage

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Viability, Efficacy, and Storage Stability of Freeze-Dried Biocontrol Agent Candida sake Using Different Protective and Rehydration Media

Journal of Food Protection ◽

10.4315/0362-028x-64.6.856 ◽

2001 ◽

Vol 64 (6) ◽

pp. 856-861 ◽

Cited By ~ 79

Author(s):

M. ABADIAS ◽

N. TEIXIDÓ ◽

J. USALL ◽

A. BENABARRE ◽

I. VIÑAS

Keyword(s):

Freeze Drying ◽

Storage Stability ◽

Storage Temperature ◽

Penicillium Expansum ◽

Freeze Dried ◽

Skimmed Milk ◽

The Stability ◽

Candida Sake ◽

Initial Starting ◽

And Storage

Viability, efficacy against Penicillium expansum on Golden Delicious apples, and storage stability of freeze-dried Candida sake strain CPA-1 were studied. The effect of several protective agents and rehydration media was investigated in the freeze drying of C. sake. Skimmed milk at 10% concentration was a good rehydration medium for all protectants tested. In general, good viability results were obtained when the same solution was used as a protectant and as a rehydration medium. The best survival was obtained when C. sake cells were protected with 10% lactose + 10% skimmed milk and rehydrated with skimmed milk (85% viability). The potential for biocontrol of the best freeze-dried treatments against P. expansum on apples was compared with that of fresh cells. Freeze-dried treatments at 1 × 107 CFU/ml reduced the incidence of decay by 45 to 66%. The best biocontrol effect was obtained with cells that had been freeze dried using 10% lactose + 10% skimmed milk as a protectant and 1% peptone as a rehydration medium, with a 66% reduction in rot incidence. However, in all treatments, the efficacy of freeze-dried cells was significantly lower than fresh cells. The stability of freeze-dried samples decreased during storage and was influenced by storage temperature. In the best treatment, storage of C. sake cells for 60 days at 4°C resulted in final concentrations of 2.5 × 108 CFU/ml, which was a 10-fold reduction in relation to the initial starting concentration of cells prior to freeze drying.

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