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Figure from:Determination of Optimum Moisture Content of Palm Nut Cracking for Efficient Production of Whole Kernel

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Figure 2: Average rate of drying of fresh palm nuts as a function of drying time.

Figure 2 Average rate of drying of fresh palm nuts as a function of drying time.

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Figure 1: Details of the static nut cracker.
Figure 1: Details of the static nut cracker.
Table 1: Legend for Figure 1. At 2 h-intervals, a randomly selected group of nuts was removed and cooled in desiccators. The drying times in this study were 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 26 h. The weights of the cooled nuts per group of nuts per drying time were obtained. The moisture content and amount of lost moisture were determined from the weight lost (ASAE, 1983; Ajibola et al., 1990; Aviara et al, 2005). After the weighing, each of the cooled nuts was subjected to cracking using a static nut cracker (Figure 1) made of mild steel. For the impact cracking, a hammer of mass 1.25 kg was dropped in the cracker from pre-determined height of about 145 mm. The hammer was a cylindrical stainless steel having diameter of 74 mm and length of 50 mm.
Table 1: Legend for Figure 1. At 2 h-intervals, a randomly selected group of nuts was removed and cooled in desiccators. The drying times in this study were 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 26 h. The weights of the cooled nuts per group of nuts per drying time were obtained. The moisture content and amount of lost moisture were determined from the weight lost (ASAE, 1983; Ajibola et al., 1990; Aviara et al, 2005). After the weighing, each of the cooled nuts was subjected to cracking using a static nut cracker (Figure 1) made of mild steel. For the impact cracking, a hammer of mass 1.25 kg was dropped in the cracker from pre-determined height of about 145 mm. The hammer was a cylindrical stainless steel having diameter of 74 mm and length of 50 mm.
Table 2: Average conditions of the nuts during the drying process.
Table 2: Average conditions of the nuts during the drying process.
Figure 3: Whole-kernel yield (%) in relation to nut moisture content (% w.b). A further decrease in the nut evaporable water retained in the nuts from 19.69 to 11.22% (corresponding to moisture content decrease from 4.18 to 2.5% wet basis or from 4.36 to 2.57% dry basis) resulted in gradual increase in the fraction of fully cracked nuts yielding whole kernels (KFC %) from 76.25% to a maximum of 84.20% and thereafter KFC decreased to 78.33% as the % evaporable water in nut decreases from 11.22% to 0% (i.e. moisture content decrease from 2.5% to 0% wet basis or from 2.57% to 0% dry basis). When the fraction of evaporable water in the intact nut was 11.22% (i.e. at nut moisture content of 2.5% wet basis or 2.57% dry basis) the KFC was 84.20% as shown in Figure 3.
Figure 3: Whole-kernel yield (%) in relation to nut moisture content (% w.b). A further decrease in the nut evaporable water retained in the nuts from 19.69 to 11.22% (corresponding to moisture content decrease from 4.18 to 2.5% wet basis or from 4.36 to 2.57% dry basis) resulted in gradual increase in the fraction of fully cracked nuts yielding whole kernels (KFC %) from 76.25% to a maximum of 84.20% and thereafter KFC decreased to 78.33% as the % evaporable water in nut decreases from 11.22% to 0% (i.e. moisture content decrease from 2.5% to 0% wet basis or from 2.57% to 0% dry basis). When the fraction of evaporable water in the intact nut was 11.22% (i.e. at nut moisture content of 2.5% wet basis or 2.57% dry basis) the KFC was 84.20% as shown in Figure 3.