ENVIROPAKWP1 - Establishment of base-line data of cashew nut stored at different temperature and Relative humidity(Maida Khan, Borges Chambal, Asmina Sulemane and Orlando Sousa)November 2004

WP1 - Establishment of base-line data of cashew nut stored at different temperature and Relative humidity

Objective : Control of moisture FFA and peroxide value at High and low RH and 3 different temperatures – Moisture– FFA– Peroxide value

FFA and Peroxide value to control de rancidity

RH : 43.2% and 83 –86.8%, Temp: 10, 25 and 35ºC

Enviropak 22.06.03

Results Effect of storage time on moisture content at three different temperatures and relative humidity

Moisture content of cashew nut samples increases during storage at High relative humidity (RH)

High and Low Temperature storage resulted im more water absorption than at 25ºC

Cashew nut at 35ºC and High RH started getting moulds from week 5th and at 10ºC and 25ºC at week 15th

Enviropak 22.06.03

Effect of storage time on FFA at three different temperatures and relative humidity

%FFA stayed constant for samples A1, A2 and B1 (25, 35ºC 43.2% and 25ºC 84.3%)

Samples stored at 10ºC and high RH, has a slight increase on the FFA from week 4th

The sample stored at 35ºC and high RH, increased extremely on week 5th (Hidrolytic deterioration of triacylglicerides can occur at high temperature and

high relative humidity – Fennema, 1996, Weiss, 1970)* * Experiment stopped at this stage due to mould attack

Enviropak 22.06.03

Effect of storage time on Peroxide value at three different temperatures and relative humidity

Sample stored at 35ºC had an increase on PV just after the 1st week – Accelerated oxidation (Fennema, 1996)

Highest increase on PV, was for sample B1 (35ºC and 43.2%) – 5.9 meq/kg of oil), after 12 weeks

increase on PV values occurred after approximately 12 weeks, suggesting that from this time autoxidation can occur for the storage conditions studied.

Enviropak 22.06.03

Severe mould attack on cashew nut samples stored

at 35ºC and 86.8 % RH

According to Allen and Hamilton (1994) the main cause of rancidity in nuts can arises via microbial attack and autoxidation under the influence of lypoxigenase.

Enviropak 22.06.03

Conclusions

Cashew nut kernels absorb moisture during storage at high relative humidity.

The temperature of storage combined with high moisture environment result in more hygroscopic product.

Hydrolytic oxidation can occur due to presence of moisture and mould attack.

Autoxidation can also occur in long storage periods when samples are stored at Low RH environment

At High Temperature storage, accelarated oxidation can also occur.

Moisture seems to be the main cause of deterioration during storage of cashew nuts.

Enviropak 22.06.03

Enviropak 24.11.04