Dehydration- -impregnation by soaking combined with impregnation by soaking combined with fermentation:

Dehydration

Dehydration- -impregnation by soaking combined with impregnation by soaking combined with fermentation:

fermentation:

an innovative alternative to traditional cured meat process an innovative alternative to traditional cured meat process

IUFoST XIII-2006, Nantes, France

Experimental set-up Experimental set-up

concentrated solution

•Salt: 50 g/kg water

•glucose syrup DE21:

950 g/water incubator at 25°C

meat fillets (beef, 7 x5 x1 cm³)

Agitating table (1.7Hz, amplitude 2 cm)

Results Results

Conclusion Conclusion

This study clearly indicated that lactic acid fermentation occurred in a meat fillet that had been previously dehydrated and impregnated with salt and sugars by DIS treatment.

Further work will aim at identifying the best meat formulation by DIS that allows optimal fermentation kinetics, and at better understanding the underlying biochemical mechanisms.

Santchurn, S.J. ¹ , Petit, T. ² , Talon, R. ³ , Trystram, G. ⁴ and Collignan, A. ¹

1Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Cirad-Réunion, Pôle agroalimentaire, Station de la Bretagne, BP20, 97408 Saint-Denis cedex 9, Réunion, France.

2Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Université de la Réunion, Saint Denis Messag. Cedex 9, Réunion, France.

3Unité Microbiologie, INRA-Theix, 63122 Saint-Genès Champanelle, France

4Unité Mixte de Recherche Génie Industriel Alimentaire, Ecole Nationale Supérieure des Industries Alimentaires (ENSIA), 1 avenue des Olympiades- 91 744 Massy Cedex, France

Abstract

An innovative combined method is being proposed for the fermentation of meat. The new process consists of two successive operations: a first dehydration-impregnation by soaking treatment (DIS) (also known as osmotic treatment ) to partially dehydrate and to impregnate the meat fillet with salt and sugars, followed by a controlled fermentation with added starter culture. This study was undertaken to evaluate the impact of meat formulation (i.e. removal of water and addition of salt and sugars) by DIS on the kinetics of fermentation.

After 24h

Inoculation of beef fillets with Lactobacillus sakei at the rate of 10

cfu/g

Incubation 25°C, RH 90%, Sampling times: 0, 8, 24 & 72 h

Dewatering-impregnation by soaking

(DIS) Fermentation

Acknowledgements Acknowledgements

The authors acknowledge the Conseil Régional de La Réunion for its financial support.

The combined treatment allowed satisfactory lactic acid fermentation of the meat, with a significant 1-log increase in the number of lactic acid bacteria (Fig.1a) accompanied by a decrease of 0.4 unit in the meat pH (Fig.1b) within a fermentation period of 72h.

An average of 0.35 g/100g (dry basis) of D-lactic acid was produced in the first 24 h of incubation, after which this amount decreased continuously to 0.14 g/100g (dry basis). Whereas L-lactic acid concentration, initially at 0.47 g/100g (dry basis), showed a continuous decrease throughout the incubation period to reach 0.14 g/100g (dry basis) at 72h. These observations suggest that both L- and D- lactic acids were utilised by microorganisms and/or other biochemical reactions during the incubation period.

After the DIS treatment, the meat fillets showed:

ƒa water loss of 32,

ƒa salt gain of 1.7, and

ƒa sugar gain of 6.6 g/100g initial mass

Analyses physicochemical:

• pH

• D- and L- lactic acid contents Microbiological:

• Lactic acid bacteria

• Yeasts

Fig. 1: Change in (a) microbial load, (b) meat pH, D- and L-lactic acid contents during fermentation of DIS-treated meat fillets

1E+06 1E+07 1E+08 1E+09 1E+10

0 25 50 75

Fermentation time (h)

1E+02 1E+03 1E+04 1E+05 1E+06

Lactic acid bacteria

yeast

(a)

Lactic acid bacteria (cfu/g) Yeast (cfu/g)

0.0 0.1 0.2 0.3 0.4 0.5

0 25 50 75

Fermentation time (h)

4.5 4.8 5.1 5.4

pH D-lactic acid

L-lactic acid

(b)

Lactic acid content (g/100g dry basis) pH